55551399 has 16 divisors (see below), whose sum is σ = 76078464. Its totient is φ = 36036000.

The previous prime is 55551389. The next prime is 55551401. The reversal of 55551399 is 99315555.

It is not a de Polignac number, because 55551399 - 2¹⁶ = 55485863 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 55551399.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55551329) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 42049 + ... + 43349.

It is an arithmetic number, because the mean of its divisors is an integer number (4754904).

Almost surely, 2^55551399 is an apocalyptic number.

55551399 is a deficient number, since it is larger than the sum of its proper divisors (20527065).

55551399 is a wasteful number, since it uses less digits than its factorization.

55551399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1678.

The product of its digits is 151875, while the sum is 42.

The square root of 55551399 is about 7453.2810895605. The cubic root of 55551399 is about 381.5618978104.

The spelling of 55551399 in words is "fifty-five million, five hundred fifty-one thousand, three hundred ninety-nine".