18902556157849 has 27 divisors (see below), whose sum is σ = 23810734247517. Its totient is φ = 14955555573504.

The previous prime is 18902556157801. The next prime is 18902556157871. The reversal of 18902556157849 is 94875165520981.

The square root of 18902556157849 is 4347707.

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

It can be written as a sum of positive squares in 4 ways, for example, as 742514826249 + 18160041331600 = 861693^2 + 4261460^2 .

It is not a de Polignac number, because 18902556157849 - 2¹⁷ = 18902556026777 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18902556157249) 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, 395617449 + ... + 395665225.

Almost surely, 2^{18902556157849} is an apocalyptic number.

18902556157849 is the 4347707-th square number.

18902556157849 is the 2173854-th centered octagonal number.

It is an amenable number.

18902556157849 is a deficient number, since it is larger than the sum of its proper divisors (4908178089668).

18902556157849 is an frugal number, since it uses more digits than its factorization.

18902556157849 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 95594 (or 47797 counting only the distinct ones).

The product of its (nonzero) digits is 217728000, while the sum is 70.

The spelling of 18902556157849 in words is "eighteen trillion, nine hundred two billion, five hundred fifty-six million, one hundred fifty-seven thousand, eight hundred forty-nine".