55644381 has 32 divisors (see below), whose sum is σ = 90693120. Its totient is φ = 33504192.

The previous prime is 55644377. The next prime is 55644403. The reversal of 55644381 is 18344655.

It is a happy number.

55644381 is a `hidden beast` number, since 5 + 5 + 644 + 3 + 8 + 1 = 666.

It is not a de Polignac number, because 55644381 - 2² = 55644377 is a prime.

It is a super-2 number, since 2×55644381² = 6192594273746322, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55644311) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 14811 + ... + 18183.

It is an arithmetic number, because the mean of its divisors is an integer number (2834160).

Almost surely, 2^55644381 is an apocalyptic number.

It is an amenable number.

55644381 is a deficient number, since it is larger than the sum of its proper divisors (35048739).

55644381 is a wasteful number, since it uses less digits than its factorization.

55644381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3442 (or 3436 counting only the distinct ones).

The product of its digits is 57600, while the sum is 36.

The square root of 55644381 is about 7459.5161371231. The cubic root of 55644381 is about 381.7746654023.

The spelling of 55644381 in words is "fifty-five million, six hundred forty-four thousand, three hundred eighty-one".