55391628 has 12 divisors (see below), whose sum is σ = 129247160. Its totient is φ = 18463872.

The previous prime is 55391621. The next prime is 55391657. The reversal of 55391628 is 82619355.

55391628 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (12).

It is not an unprimeable number, because it can be changed into a prime (55391621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2307973 + ... + 2307996.

Almost surely, 2^55391628 is an apocalyptic number.

It is an amenable number.

55391628 is an abundant number, since it is smaller than the sum of its proper divisors (73855532).

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

55391628 is a wasteful number, since it uses less digits than its factorization.

55391628 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4615976 (or 4615974 counting only the distinct ones).

The product of its digits is 64800, while the sum is 39.

The square root of 55391628 is about 7442.5552063791. Note that the first 3 decimals coincide. The cubic root of 55391628 is about 381.1957440305.

The spelling of 55391628 in words is "fifty-five million, three hundred ninety-one thousand, six hundred twenty-eight".