55321615 has 4 divisors (see below), whose sum is σ = 66385944. Its totient is φ = 44257288.

The previous prime is 55321579. The next prime is 55321627. The reversal of 55321615 is 51612355.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 55321615 - 2¹¹ = 55319567 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 5532157 + ... + 5532166.

It is an arithmetic number, because the mean of its divisors is an integer number (16596486).

Almost surely, 2^55321615 is an apocalyptic number.

55321615 is a deficient number, since it is larger than the sum of its proper divisors (11064329).

55321615 is a wasteful number, since it uses less digits than its factorization.

55321615 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11064328.

The product of its digits is 4500, while the sum is 28.

The square root of 55321615 is about 7437.8501598244. The cubic root of 55321615 is about 381.0350704715.

The spelling of 55321615 in words is "fifty-five million, three hundred twenty-one thousand, six hundred fifteen".