261499929600 has 2112 divisors, whose sum is σ = 1178996539392. Its totient is φ = 49545216000.

The previous prime is 261499929599. The next prime is 261499929601. The reversal of 261499929600 is 6929994162.

It is an interprime number because it is at equal distance from previous prime (261499929599) and next prime (261499929601).

It is not an unprimeable number, because it can be changed into a prime (261499929601) by changing a digit.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 3683097565 + ... + 3683097635.

Almost surely, 2^261499929600 is an apocalyptic number.

261499929600 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 261499929600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (589498269696).

261499929600 is an abundant number, since it is smaller than the sum of its proper divisors (917496609792).

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

261499929600 is a wasteful number, since it uses less digits than its factorization.

261499929600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 172 (or 149 counting only the distinct ones).

The product of its (nonzero) digits is 3779136, while the sum is 57.

The spelling of 261499929600 in words is "two hundred sixty-one billion, four hundred ninety-nine million, nine hundred twenty-nine thousand, six hundred".