261646656343725 has 24 divisors (see below), whose sum is σ = 458035558401600. Its totient is φ = 131336360830720.

The previous prime is 261646656343651. The next prime is 261646656343727. The reversal of 261646656343725 is 527343656646162.

It is a happy number.

It is not a de Polignac number, because 261646656343725 - 2¹⁴ = 261646656327341 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261646656343727) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 102606530625 + ... + 102606533174.

It is an arithmetic number, because the mean of its divisors is an integer number (19084814933400).

Almost surely, 2^{261646656343725} is an apocalyptic number.

261646656343725 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

261646656343725 is a deficient number, since it is larger than the sum of its proper divisors (196388902057875).

261646656343725 is a wasteful number, since it uses less digits than its factorization.

261646656343725 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 205213063829 (or 205213063824 counting only the distinct ones).

The product of its digits is 783820800, while the sum is 66.

The spelling of 261646656343725 in words is "two hundred sixty-one trillion, six hundred forty-six billion, six hundred fifty-six million, three hundred forty-three thousand, seven hundred twenty-five".