261551600 has 30 divisors (see below), whose sum is σ = 628378680. Its totient is φ = 104620480.

The previous prime is 261551599. The next prime is 261551617. The reversal of 261551600 is 6155162.

It is a self number, because there is not a number n which added to its sum of digits gives 261551600.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 326540 + ... + 327339.

It is an arithmetic number, because the mean of its divisors is an integer number (20945956).

Almost surely, 2^261551600 is an apocalyptic number.

261551600 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

261551600 is an abundant number, since it is smaller than the sum of its proper divisors (366827080).

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

261551600 is a wasteful number, since it uses less digits than its factorization.

261551600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 653897 (or 653886 counting only the distinct ones).

The product of its (nonzero) digits is 1800, while the sum is 26.

The square root of 261551600 is about 16172.5570025275. The cubic root of 261551600 is about 639.5175400378.

The spelling of 261551600 in words is "two hundred sixty-one million, five hundred fifty-one thousand, six hundred".