55400215 has 16 divisors (see below), whose sum is σ = 74708928. Its totient is φ = 39131136.

The previous prime is 55400203. The next prime is 55400243. The reversal of 55400215 is 51200455.

55400215 = T₁₆₆₆ + T₁₆₆₇ + ... + T₁₇₀₄.

It is a cyclic number.

It is not a de Polignac number, because 55400215 - 2¹⁵ = 55367447 is a prime.

It is a Duffinian number.

It is a congruent 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, 17034 + ... + 20023.

It is an arithmetic number, because the mean of its divisors is an integer number (4669308).

Almost surely, 2^55400215 is an apocalyptic number.

55400215 is a deficient number, since it is larger than the sum of its proper divisors (19308713).

55400215 is a wasteful number, since it uses less digits than its factorization.

55400215 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37098.

The product of its (nonzero) digits is 1000, while the sum is 22.

The square root of 55400215 is about 7443.1320692300. The cubic root of 55400215 is about 381.2154411029.

The spelling of 55400215 in words is "fifty-five million, four hundred thousand, two hundred fifteen".