625631958961 has 3 divisors (see below), whose sum is σ = 625632749931. Its totient is φ = 625631167992.

The previous prime is 625631958949. The next prime is 625631958971. The reversal of 625631958961 is 169859136526.

The square root of 625631958961 is 790969.

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., 601370781361 + 24261177600 = 775481^2 + 155760^2 .

It is a de Polignac number, because none of the positive numbers 2^k-625631958961 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 625631958961.

It is not an unprimeable number, because it can be changed into a prime (625631958971) 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, 395485 + ... + 1186453.

It is an arithmetic number, because the mean of its divisors is an integer number (208544249977).

Almost surely, 2^625631958961 is an apocalyptic number.

625631958961 is the 790969-th square number.

625631958961 is the 395485-th centered octagonal number.

It is an amenable number.

625631958961 is a deficient number, since it is larger than the sum of its proper divisors (790970).

625631958961 is an frugal number, since it uses more digits than its factorization.

625631958961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1581938 (or 790969 counting only the distinct ones).

The product of its digits is 20995200, while the sum is 61.

The spelling of 625631958961 in words is "six hundred twenty-five billion, six hundred thirty-one million, nine hundred fifty-eight thousand, nine hundred sixty-one".