55661904 has 100 divisors (see below), whose sum is σ = 166769460. Its totient is φ = 17902080.

The previous prime is 55661891. The next prime is 55661939. The reversal of 55661904 is 40916655.

55661904 is a `hidden beast` number, since 5 + 566 + 1 + 90 + 4 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 26501904 + 29160000 = 5148^2 + 5400^2 .

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 pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 36844 + ... + 38324.

Almost surely, 2^55661904 is an apocalyptic number.

55661904 is a gapful number since it is divisible by the number (54) 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 55661904, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (83384730).

55661904 is an abundant number, since it is smaller than the sum of its proper divisors (111107556).

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

55661904 is a wasteful number, since it uses less digits than its factorization.

55661904 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1530 (or 1515 counting only the distinct ones).

The product of its (nonzero) digits is 32400, while the sum is 36.

The square root of 55661904 is about 7460.6905846577. The cubic root of 55661904 is about 381.8147361470.

It can be divided in two parts, 55661 and 904, that added together give a palindrome (56565).

The spelling of 55661904 in words is "fifty-five million, six hundred sixty-one thousand, nine hundred four".