55421515 has 16 divisors (see below), whose sum is σ = 67516416. Its totient is φ = 43669600.

The previous prime is 55421503. The next prime is 55421533. The reversal of 55421515 is 51512455.

It is a de Polignac number, because none of the positive numbers 2^k-55421515 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 124884 + ... + 125326.

It is an arithmetic number, because the mean of its divisors is an integer number (4219776).

Almost surely, 2^55421515 is an apocalyptic number.

55421515 is a deficient number, since it is larger than the sum of its proper divisors (12094901).

55421515 is a wasteful number, since it uses less digits than its factorization.

55421515 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 770.

The product of its digits is 5000, while the sum is 28.

The square root of 55421515 is about 7444.5627809832. The cubic root of 55421515 is about 381.2642907839.

The spelling of 55421515 in words is "fifty-five million, four hundred twenty-one thousand, five hundred fifteen".