55215399 has 8 divisors (see below), whose sum is σ = 73657072. Its totient is φ = 36792000.

The previous prime is 55215389. The next prime is 55215421. The reversal of 55215399 is 99351255.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 55215399 - 2⁴ = 55215383 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55215319) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5937 + ... + 12069.

It is an arithmetic number, because the mean of its divisors is an integer number (9207134).

Almost surely, 2^55215399 is an apocalyptic number.

55215399 is a deficient number, since it is larger than the sum of its proper divisors (18441673).

55215399 is a wasteful number, since it uses less digits than its factorization.

55215399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9137.

The product of its digits is 60750, while the sum is 39.

The square root of 55215399 is about 7430.7064940018. The cubic root of 55215399 is about 380.7910552378.

It can be divided in two parts, 552 and 15399, that added together give a palindrome (15951).

The spelling of 55215399 in words is "fifty-five million, two hundred fifteen thousand, three hundred ninety-nine".