2178862353409 has 27 divisors (see below), whose sum is σ = 2545689335427. Its totient is φ = 1859457104064.

The previous prime is 2178862353391. The next prime is 2178862353457. The reversal of 2178862353409 is 9043532688712.

It is a happy number.

The square root of 2178862353409 is 1476097.

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

It can be written as a sum of positive squares in only one way, i.e., 244337433025 + 1934524920384 = 494305^2 + 1390872^2 .

It is not a de Polignac number, because 2178862353409 - 2³⁷ = 2041423399937 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2178862353209) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 4474049764 + ... + 4474050250.

It is an arithmetic number, because the mean of its divisors is an integer number (94284790201).

It is a 1-persistent number, because it is pandigital, but 2⋅2178862353409 = 4357724706818 is not.

Almost surely, 2^{2178862353409} is an apocalyptic number.

2178862353409 is the 1476097-th square number.

2178862353409 is the 738049-th centered octagonal number.

It is an amenable number.

2178862353409 is a deficient number, since it is larger than the sum of its proper divisors (366826982018).

2178862353409 is an frugal number, since it uses more digits than its factorization.

2178862353409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1854 (or 927 counting only the distinct ones).

The product of its (nonzero) digits is 17418240, while the sum is 58.

The spelling of 2178862353409 in words is "two trillion, one hundred seventy-eight billion, eight hundred sixty-two million, three hundred fifty-three thousand, four hundred nine".