55645521 has 16 divisors (see below), whose sum is σ = 76429248. Its totient is φ = 35985600.

The previous prime is 55645517. The next prime is 55645523. The reversal of 55645521 is 12554655.

It is not a de Polignac number, because 55645521 - 2² = 55645517 is a prime.

It is a super-2 number, since 2×55645521² = 6192848014722882, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (55645523) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 53991 + ... + 55011.

It is an arithmetic number, because the mean of its divisors is an integer number (4776828).

Almost surely, 2^55645521 is an apocalyptic number.

It is an amenable number.

55645521 is a deficient number, since it is larger than the sum of its proper divisors (20783727).

55645521 is a wasteful number, since it uses less digits than its factorization.

55645521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1552.

The product of its digits is 30000, while the sum is 33.

The square root of 55645521 is about 7459.5925491946. The cubic root of 55645521 is about 381.7772725547. Note that the first 3 decimals are identical.

The spelling of 55645521 in words is "fifty-five million, six hundred forty-five thousand, five hundred twenty-one".