265647981 has 12 divisors (see below), whose sum is σ = 355703712. Its totient is φ = 176348304.

The previous prime is 265647973. The next prime is 265648013. The reversal of 265647981 is 189746562.

It is not a de Polignac number, because 265647981 - 2³ = 265647973 is a prime.

It is a super-2 number, since 2×265647981² = 141137699618752722, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 265647981.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (265647931) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 365040 + ... + 365766.

It is an arithmetic number, because the mean of its divisors is an integer number (29641976).

Almost surely, 2^265647981 is an apocalyptic number.

It is an amenable number.

265647981 is a deficient number, since it is larger than the sum of its proper divisors (90055731).

265647981 is an frugal number, since it uses more digits than its factorization.

265647981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1428 (or 1079 counting only the distinct ones).

The product of its digits is 725760, while the sum is 48.

The square root of 265647981 is about 16298.7110226545. The cubic root of 265647981 is about 642.8389353644.

The spelling of 265647981 in words is "two hundred sixty-five million, six hundred forty-seven thousand, nine hundred eighty-one".