55561644 has 36 divisors (see below), whose sum is σ = 148710744. Its totient is φ = 17430912.

The previous prime is 55561631. The next prime is 55561663. The reversal of 55561644 is 44616555.

55561644 is a `hidden beast` number, since 5 + 5 + 5 + 6 + 1 + 644 = 666.

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

It is a super-3 number, since 3×55561644³ (a number of 24 digits) contains 333 as substring.

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

It is a junction number, because it is equal to n+sod(n) for n = 55561599 and 55561608.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 44782 + ... + 46005.

It is an arithmetic number, because the mean of its divisors is an integer number (4130854).

Almost surely, 2^55561644 is an apocalyptic number.

It is an amenable number.

55561644 is an abundant number, since it is smaller than the sum of its proper divisors (93149100).

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

55561644 is a wasteful number, since it uses less digits than its factorization.

55561644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90814 (or 90809 counting only the distinct ones).

The product of its digits is 72000, while the sum is 36.

The square root of 55561644 is about 7453.9683390795. The cubic root of 55561644 is about 381.5853527334.

The spelling of 55561644 in words is "fifty-five million, five hundred sixty-one thousand, six hundred forty-four".