55681920 has 192 divisors, whose sum is σ = 219903840. Its totient is φ = 12718080.

The previous prime is 55681907. The next prime is 55681933. The reversal of 55681920 is 2918655.

It is a happy number.

55681920 is a `hidden beast` number, since 5 + 568 + 1 + 92 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (55681907) and next prime (55681933).

It is a tau number, because it is divible by the number of its divisors (192).

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 polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 39630 + ... + 41010.

Almost surely, 2^55681920 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 55681920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (109951920).

55681920 is an abundant number, since it is smaller than the sum of its proper divisors (164221920).

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

55681920 is a wasteful number, since it uses less digits than its factorization.

55681920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1413 (or 1398 counting only the distinct ones).

The product of its (nonzero) digits is 21600, while the sum is 36.

The square root of 55681920 is about 7462.0318948662. The cubic root of 55681920 is about 381.8604974746.

The spelling of 55681920 in words is "fifty-five million, six hundred eighty-one thousand, nine hundred twenty".