55391616 has 96 divisors (see below), whose sum is σ = 182192400. Its totient is φ = 15823872.

The previous prime is 55391603. The next prime is 55391617. The reversal of 55391616 is 61619355.

55391616 is a `hidden beast` number, since 5 + 5 + 39 + 1 + 616 = 666.

It is a tau number, because it is divible by the number of its divisors (96).

It is a super-2 number, since 2×55391616² = 6136462246182912, which contains 22 as substring.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55391617) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 4630 + ... + 11498.

Almost surely, 2^55391616 is an apocalyptic number.

55391616 is a gapful number since it is divisible by the number (56) 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 55391616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (91096200).

55391616 is an abundant number, since it is smaller than the sum of its proper divisors (126800784).

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

55391616 is a wasteful number, since it uses less digits than its factorization.

55391616 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6896 (or 6881 counting only the distinct ones).

The product of its digits is 24300, while the sum is 36.

The square root of 55391616 is about 7442.5544002043. The cubic root of 55391616 is about 381.1957165032.

The spelling of 55391616 in words is "fifty-five million, three hundred ninety-one thousand, six hundred sixteen".