261432299520 has 1664 divisors, whose sum is σ = 1171955174400. Its totient is φ = 53905195008.

The previous prime is 261432299507. The next prime is 261432299539. The reversal of 261432299520 is 25992234162.

261432299520 is a `hidden beast` number, since 2 + 6 + 1 + 4 + 32 + 2 + 99 + 520 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 1908264892 + ... + 1908265028.

Almost surely, 2^261432299520 is an apocalyptic number.

261432299520 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 261432299520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (585977587200).

261432299520 is an abundant number, since it is smaller than the sum of its proper divisors (910522874880).

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

261432299520 is a wasteful number, since it uses less digits than its factorization.

261432299520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 228 (or 200 counting only the distinct ones).

The product of its (nonzero) digits is 466560, while the sum is 45.

The spelling of 261432299520 in words is "two hundred sixty-one billion, four hundred thirty-two million, two hundred ninety-nine thousand, five hundred twenty".