55510921 has 4 divisors (see below), whose sum is σ = 55552000. Its totient is φ = 55469844.

The previous prime is 55510919. The next prime is 55510927. The reversal of 55510921 is 12901555.

55510921 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 55510921 - 2¹ = 55510919 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 55510921.

It is not an unprimeable number, because it can be changed into a prime (55510927) 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, 18441 + ... + 21238.

It is an arithmetic number, because the mean of its divisors is an integer number (13888000).

Almost surely, 2^55510921 is an apocalyptic number.

It is an amenable number.

55510921 is a deficient number, since it is larger than the sum of its proper divisors (41079).

55510921 is a wasteful number, since it uses less digits than its factorization.

55510921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41078.

The product of its (nonzero) digits is 2250, while the sum is 28.

The square root of 55510921 is about 7450.5651463496. The cubic root of 55510921 is about 381.4691991827.

It can be divided in two parts, 555 and 10921, that added together give a triangular number (11476 = T₁₅₁).

The spelling of 55510921 in words is "fifty-five million, five hundred ten thousand, nine hundred twenty-one".