261351417600 has 1944 divisors, whose sum is σ = 1242369077040. Its totient is φ = 51774750720.

The previous prime is 261351417557. The next prime is 261351417623. The reversal of 261351417600 is 6714153162.

261351417600 is a `hidden beast` number, since 2 + 6 + 1 + 3 + 5 + 1 + 41 + 7 + 600 = 666.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 215 ways as a sum of consecutive naturals, for example, 623750191 + ... + 623750609.

Almost surely, 2^261351417600 is an apocalyptic number.

261351417600 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 261351417600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (621184538520).

261351417600 is an abundant number, since it is smaller than the sum of its proper divisors (981017659440).

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

261351417600 is a wasteful number, since it uses less digits than its factorization.

261351417600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 495 (or 466 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 36.

The spelling of 261351417600 in words is "two hundred sixty-one billion, three hundred fifty-one million, four hundred seventeen thousand, six hundred".