261572520 has 128 divisors (see below), whose sum is σ = 868423680. Its totient is φ = 62496000.

The previous prime is 261572501. The next prime is 261572539. The reversal of 261572520 is 25275162.

It is an interprime number because it is at equal distance from previous prime (261572501) and next prime (261572539).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 92325 + ... + 95115.

It is an arithmetic number, because the mean of its divisors is an integer number (6784560).

Almost surely, 2^261572520 is an apocalyptic number.

261572520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 261572520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (434211840).

261572520 is an abundant number, since it is smaller than the sum of its proper divisors (606851160).

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

261572520 is a wasteful number, since it uses less digits than its factorization.

261572520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2887 (or 2883 counting only the distinct ones).

The product of its (nonzero) digits is 8400, while the sum is 30.

The square root of 261572520 is about 16173.2037642515. The cubic root of 261572520 is about 639.5345900199.

The spelling of 261572520 in words is "two hundred sixty-one million, five hundred seventy-two thousand, five hundred twenty".