55540491 has 4 divisors (see below), whose sum is σ = 74053992. Its totient is φ = 37026992.

The previous prime is 55540487. The next prime is 55540519. The reversal of 55540491 is 19404555.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 55540491 - 2² = 55540487 is a prime.

It is a super-2 number, since 2×55540491² = 6169492281042162, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (55540451) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9256746 + ... + 9256751.

It is an arithmetic number, because the mean of its divisors is an integer number (18513498).

Almost surely, 2^55540491 is an apocalyptic number.

55540491 is a deficient number, since it is larger than the sum of its proper divisors (18513501).

55540491 is a wasteful number, since it uses less digits than its factorization.

55540491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18513500.

The product of its (nonzero) digits is 18000, while the sum is 33.

The square root of 55540491 is about 7452.5492953754. The cubic root of 55540491 is about 381.5369218440.

The spelling of 55540491 in words is "fifty-five million, five hundred forty thousand, four hundred ninety-one".