55646438399 has 4 divisors (see below), whose sum is σ = 55827697464. Its totient is φ = 55465179336.

The previous prime is 55646438383. The next prime is 55646438413. The reversal of 55646438399 is 99383464655.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 99383464655 = 5 ⋅19876692931.

It is a cyclic number.

It is not a de Polignac number, because 55646438399 - 2⁴ = 55646438383 is a prime.

It is a super-2 number, since 2×55646438399² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55646438339) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 90629072 + ... + 90629685.

It is an arithmetic number, because the mean of its divisors is an integer number (13956924366).

Almost surely, 2^55646438399 is an apocalyptic number.

55646438399 is a deficient number, since it is larger than the sum of its proper divisors (181259065).

55646438399 is a wasteful number, since it uses less digits than its factorization.

55646438399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 181259064.

The product of its digits is 83980800, while the sum is 62.

The spelling of 55646438399 in words is "fifty-five billion, six hundred forty-six million, four hundred thirty-eight thousand, three hundred ninety-nine".