625097378161 has 9 divisors (see below), whose sum is σ = 626809018251. Its totient is φ = 623390405832.

The previous prime is 625097378123. The next prime is 625097378173. The reversal of 625097378161 is 161873790526.

The square root of 625097378161 is 790631.

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., 238158640225 + 386938737936 = 488015^2 + 622044^2 .

It is a de Polignac number, because none of the positive numbers 2^k-625097378161 is a prime.

It is a super-3 number, since 3×625097378161³ (a number of 36 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (625097378111) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 369223831 + ... + 369225523.

Almost surely, 2^625097378161 is an apocalyptic number.

625097378161 is the 790631-st square number.

625097378161 is the 395316-th centered octagonal number.

It is an amenable number.

625097378161 is a deficient number, since it is larger than the sum of its proper divisors (1711640090).

625097378161 is an frugal number, since it uses more digits than its factorization.

625097378161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4320 (or 2160 counting only the distinct ones).

The product of its (nonzero) digits is 3810240, while the sum is 55.

The spelling of 625097378161 in words is "six hundred twenty-five billion, ninety-seven million, three hundred seventy-eight thousand, one hundred sixty-one".