55664440 has 64 divisors (see below), whose sum is σ = 135898560. Its totient is φ = 20398080.

The previous prime is 55664431. The next prime is 55664449. The reversal of 55664440 is 4446655.

It is an interprime number because it is at equal distance from previous prime (55664431) and next prime (55664449).

It is a junction number, because it is equal to n+sod(n) for n = 55664396 and 55664405.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55664449) 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, 86520 + ... + 87160.

It is an arithmetic number, because the mean of its divisors is an integer number (2123415).

Almost surely, 2^55664440 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 55664440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (67949280).

55664440 is an abundant number, since it is smaller than the sum of its proper divisors (80234120).

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

55664440 is a wasteful number, since it uses less digits than its factorization.

55664440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 832 (or 828 counting only the distinct ones).

The product of its (nonzero) digits is 57600, while the sum is 34.

The square root of 55664440 is about 7460.8605401790. The cubic root of 55664440 is about 381.8205346519.

The spelling of 55664440 in words is "fifty-five million, six hundred sixty-four thousand, four hundred forty".