1213773121 has 4 divisors (see below), whose sum is σ = 1324116144. Its totient is φ = 1103430100.

The previous prime is 1213773079. The next prime is 1213773131.

1213773121 is nontrivially palindromic in base 10.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1213773121 - 2¹⁷ = 1213642049 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1213773121.

It is not an unprimeable number, because it can be changed into a prime (1213773131) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 55171495 + ... + 55171516.

It is an arithmetic number, because the mean of its divisors is an integer number (331029036).

Almost surely, 2^1213773121 is an apocalyptic number.

1213773121 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1213773121 is a deficient number, since it is larger than the sum of its proper divisors (110343023).

1213773121 is a wasteful number, since it uses less digits than its factorization.

1213773121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 110343022.

The product of its digits is 1764, while the sum is 28.

The square root of 1213773121 is about 34839.2468489203. The cubic root of 1213773121 is about 1066.7087034974.

It can be divided in two parts, 12137 and 73121, that added together give a palindrome (85258).

The spelling of 1213773121 in words is "one billion, two hundred thirteen million, seven hundred seventy-three thousand, one hundred twenty-one".