55231640 has 32 divisors (see below), whose sum is σ = 131582880. Its totient is φ = 20792832.

The previous prime is 55231621. The next prime is 55231663. The reversal of 55231640 is 4613255.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 39932 + ... + 41291.

It is an arithmetic number, because the mean of its divisors is an integer number (4111965).

Almost surely, 2^55231640 is an apocalyptic number.

It is an amenable number.

55231640 is an abundant number, since it is smaller than the sum of its proper divisors (76351240).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

55231640 is a wasteful number, since it uses less digits than its factorization.

55231640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81251 (or 81247 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 26.

The square root of 55231640 is about 7431.7992437902. The cubic root of 55231640 is about 380.8283867394.

Adding to 55231640 its reverse (4613255), we get a palindrome (59844895).

The spelling of 55231640 in words is "fifty-five million, two hundred thirty-one thousand, six hundred forty".