1234567654321 has 9 divisors (see below), whose sum is σ = 1240021551211. Its totient is φ = 1229137654864.

The previous prime is 1234567654301. The next prime is 1234567654337.

The square root of 1234567654321 is 1111111.

It is a perfect power (a square), and thus also a powerful number.

1234567654321 is nontrivially palindromic in base 10.

1234567654321 is an esthetic number in base 10, because in such base its adjacent digits differ by 1.

It can be written as a sum of positive squares in only one way, i.e., 1208154903921 + 26412750400 = 1099161^2 + 162520^2 .

It is not a de Polignac number, because 1234567654321 - 2⁵ = 1234567654289 is a prime.

It is a super-2 number, since 2×1234567654321² (a number of 25 digits) contains 22 as substring.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1234567654301) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 265553205 + ... + 265557853.

Almost surely, 2^{1234567654321} is an apocalyptic number.

1234567654321 is the 1111111-st square number.

1234567654321 is the 555556-th centered octagonal number.

It is an amenable number.

1234567654321 is a deficient number, since it is larger than the sum of its proper divisors (5453896890).

1234567654321 is an frugal number, since it uses more digits than its factorization.

1234567654321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9776 (or 4888 counting only the distinct ones).

The product of its digits is 3628800, while the sum is 49.

Multiplying 1234567654321 by its sum of digits (49), we get a square (60493815061729 = 7777777²).

It can be divided in two parts, 123456 and 7654321, that added together give a palindrome (7777777).

The spelling of 1234567654321 in words is "one trillion, two hundred thirty-four billion, five hundred sixty-seven million, six hundred fifty-four thousand, three hundred twenty-one".