265979520261 has 224 divisors, whose sum is σ = 547082000640. Its totient is φ = 125084362752.

The previous prime is 265979520259. The next prime is 265979520281. The reversal of 265979520261 is 162025979562.

265979520261 is a `hidden beast` number, since 2 + 6 + 5 + 97 + 9 + 520 + 26 + 1 = 666.

It is not a de Polignac number, because 265979520261 - 2¹ = 265979520259 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 265979520198 and 265979520207.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (265979520221) by changing a digit.

It is a polite number, since it can be written in 223 ways as a sum of consecutive naturals, for example, 21421291 + ... + 21433703.

It is an arithmetic number, because the mean of its divisors is an integer number (2442330360).

Almost surely, 2^265979520261 is an apocalyptic number.

265979520261 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

265979520261 is an abundant number, since it is smaller than the sum of its proper divisors (281102480379).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

265979520261 is a wasteful number, since it uses less digits than its factorization.

265979520261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12487 (or 12472 counting only the distinct ones).

The product of its (nonzero) digits is 4082400, while the sum is 54.

The spelling of 265979520261 in words is "two hundred sixty-five billion, nine hundred seventy-nine million, five hundred twenty thousand, two hundred sixty-one".