261622872 has 160 divisors (see below), whose sum is σ = 845586720. Its totient is φ = 74027520.

The previous prime is 261622849. The next prime is 261622939. The reversal of 261622872 is 278226162.

261622872 is a `hidden beast` number, since 26 + 1 + 622 + 8 + 7 + 2 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 621222 + ... + 621642.

It is an arithmetic number, because the mean of its divisors is an integer number (5284917).

Almost surely, 2^261622872 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 261622872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (422793360).

261622872 is an abundant number, since it is smaller than the sum of its proper divisors (583963848).

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

261622872 is a wasteful number, since it uses less digits than its factorization.

261622872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 583 (or 570 counting only the distinct ones).

The product of its digits is 32256, while the sum is 36.

The square root of 261622872 is about 16174.7603382554. The cubic root of 261622872 is about 639.5756236112.

The spelling of 261622872 in words is "two hundred sixty-one million, six hundred twenty-two thousand, eight hundred seventy-two".