261626904 has 192 divisors, whose sum is σ = 905748480. Its totient is φ = 66240000.

The previous prime is 261626891. The next prime is 261626929. The reversal of 261626904 is 409626162.

261626904 is a `hidden beast` number, since 26 + 1 + 626 + 9 + 0 + 4 = 666.

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

It is a zygodrome in base 2.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 226729 + ... + 227879.

It is an arithmetic number, because the mean of its divisors is an integer number (4717440).

Almost surely, 2^261626904 is an apocalyptic number.

261626904 is a gapful number since it is divisible by the number (24) 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 261626904, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (452874240).

261626904 is an abundant number, since it is smaller than the sum of its proper divisors (644121576).

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

261626904 is a wasteful number, since it uses less digits than its factorization.

261626904 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1222 (or 1215 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 36.

The square root of 261626904 is about 16174.8849764071. The cubic root of 261626904 is about 639.5789092001.

The spelling of 261626904 in words is "two hundred sixty-one million, six hundred twenty-six thousand, nine hundred four".