261626220 has 48 divisors (see below), whose sum is σ = 813949920. Its totient is φ = 69766848.

The previous prime is 261626203. The next prime is 261626227. The reversal of 261626220 is 22626162.

261626220 is a `hidden beast` number, since 2 + 616 + 26 + 2 + 20 = 666.

261626220 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (261626227) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 241707 + ... + 242786.

It is an arithmetic number, because the mean of its divisors is an integer number (16957290).

Almost surely, 2^261626220 is an apocalyptic number.

261626220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

261626220 is an abundant number, since it is smaller than the sum of its proper divisors (552323700).

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

261626220 is a wasteful number, since it uses less digits than its factorization.

261626220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 484511 (or 484503 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 27.

The square root of 261626220 is about 16174.8638325026. The cubic root of 261626220 is about 639.5783518258.

The spelling of 261626220 in words is "two hundred sixty-one million, six hundred twenty-six thousand, two hundred twenty".