55520997 has 16 divisors (see below), whose sum is σ = 89580672. Its totient is φ = 29859840.

The previous prime is 55520977. The next prime is 55521001. The reversal of 55520997 is 79902555.

It is not a de Polignac number, because 55520997 - 2⁸ = 55520741 is a prime.

It is a super-2 number, since 2×55520997² = 6165162215748018, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55520977) 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, 77404 + ... + 78117.

It is an arithmetic number, because the mean of its divisors is an integer number (5598792).

Almost surely, 2^55520997 is an apocalyptic number.

It is an amenable number.

55520997 is a deficient number, since it is larger than the sum of its proper divisors (34059675).

55520997 is a wasteful number, since it uses less digits than its factorization.

55520997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 155548.

The product of its (nonzero) digits is 141750, while the sum is 42.

The square root of 55520997 is about 7451.2413059839. The cubic root of 55520997 is about 381.4922784318.

The spelling of 55520997 in words is "fifty-five million, five hundred twenty thousand, nine hundred ninety-seven".