625726661091841 has 3 divisors (see below), whose sum is σ = 625726686106371. Its totient is φ = 625726636077312.

The previous prime is 625726661091781. The next prime is 625726661091859. The reversal of 625726661091841 is 148190166627526.

The square root of 625726661091841 is 25014529.

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

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 176935994389441 + 448790666702400 = 13301729^2 + 21184680^2 .

It is not a de Polignac number, because 625726661091841 - 2²⁵ = 625726627537409 is a prime.

It is a super-2 number, since 2×625726661091841² (a number of 30 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (625726661091881) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 12507265 + ... + 37521793.

It is an arithmetic number, because the mean of its divisors is an integer number (208575562035457).

Almost surely, 2^{625726661091841} is an apocalyptic number.

625726661091841 is the 25014529-th square number.

625726661091841 is the 12507265-th centered octagonal number.

It is an amenable number.

625726661091841 is a deficient number, since it is larger than the sum of its proper divisors (25014530).

625726661091841 is an frugal number, since it uses more digits than its factorization.

625726661091841 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50029058 (or 25014529 counting only the distinct ones).

The product of its (nonzero) digits is 52254720, while the sum is 64.

The spelling of 625726661091841 in words is "six hundred twenty-five trillion, seven hundred twenty-six billion, six hundred sixty-one million, ninety-one thousand, eight hundred forty-one".