261555948 has 36 divisors (see below), whose sum is σ = 700048440. Its totient is φ = 82056576.

The previous prime is 261555913. The next prime is 261555949. The reversal of 261555948 is 849555162.

261555948 is a `hidden beast` number, since 2 + 6 + 1 + 55 + 594 + 8 = 666.

It is a tau number, because it is divible by the number of its divisors (36).

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (261555949) by changing a digit.

It is an upside-down number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 213078 + ... + 214301.

It is an arithmetic number, because the mean of its divisors is an integer number (19445790).

Almost surely, 2^261555948 is an apocalyptic number.

It is an amenable number.

261555948 is an abundant number, since it is smaller than the sum of its proper divisors (438492492).

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

261555948 is a wasteful number, since it uses less digits than its factorization.

261555948 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 427406 (or 427401 counting only the distinct ones).

The product of its digits is 432000, while the sum is 45.

The square root of 261555948 is about 16172.6914272177. The cubic root of 261555948 is about 639.5210837705.

The spelling of 261555948 in words is "two hundred sixty-one million, five hundred fifty-five thousand, nine hundred forty-eight".