55621656 has 48 divisors (see below), whose sum is σ = 154720800. Its totient is φ = 18038592.

The previous prime is 55621649. The next prime is 55621663. The reversal of 55621656 is 65612655.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (55621649) and next prime (55621663).

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

It is a self number, because there is not a number n which added to its sum of digits gives 55621656.

It is a congruent number.

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, 7776 + ... + 13103.

It is an arithmetic number, because the mean of its divisors is an integer number (3223350).

Almost surely, 2^55621656 is an apocalyptic number.

It is an amenable number.

55621656 is an abundant number, since it is smaller than the sum of its proper divisors (99099144).

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

55621656 is a wasteful number, since it uses less digits than its factorization.

55621656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20928 (or 20921 counting only the distinct ones).

The product of its digits is 54000, while the sum is 36.

The square root of 55621656 is about 7457.9927594494. The cubic root of 55621656 is about 381.7226864457.

Subtracting 55621656 from its reverse (65612655), we obtain a palindrome (9990999).

The spelling of 55621656 in words is "fifty-five million, six hundred twenty-one thousand, six hundred fifty-six".