55721580 has 48 divisors (see below), whose sum is σ = 165201120. Its totient is φ = 13984768.

The previous prime is 55721579. The next prime is 55721629. The reversal of 55721580 is 8512755.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 26295 + ... + 28334.

It is an arithmetic number, because the mean of its divisors is an integer number (3441690).

Almost surely, 2^55721580 is an apocalyptic number.

It is an amenable number.

55721580 is an abundant number, since it is smaller than the sum of its proper divisors (109479540).

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

55721580 is a wasteful number, since it uses less digits than its factorization.

55721580 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54658 (or 54656 counting only the distinct ones).

The product of its (nonzero) digits is 14000, while the sum is 33.

The square root of 55721580 is about 7464.6888749632. The cubic root of 55721580 is about 381.9511372677.

The spelling of 55721580 in words is "fifty-five million, seven hundred twenty-one thousand, five hundred eighty".