55881391 has 2 divisors, whose sum is σ = 55881392. Its totient is φ = 55881390.

The previous prime is 55881383. The next prime is 55881403. The reversal of 55881391 is 19318855.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 55881391 - 2³ = 55881383 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (55881491) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27940695 + 27940696.

It is an arithmetic number, because the mean of its divisors is an integer number (27940696).

Almost surely, 2^55881391 is an apocalyptic number.

55881391 is a deficient number, since it is larger than the sum of its proper divisors (1).

55881391 is an equidigital number, since it uses as much as digits as its factorization.

55881391 is an evil number, because the sum of its binary digits is even.

The product of its digits is 43200, while the sum is 40.

The square root of 55881391 is about 7475.3856756692. The cubic root of 55881391 is about 382.3159374715.

The spelling of 55881391 in words is "fifty-five million, eight hundred eighty-one thousand, three hundred ninety-one".