55431691 has 6 divisors (see below), whose sum is σ = 64481820. Its totient is φ = 47512836.

The previous prime is 55431653. The next prime is 55431703. The reversal of 55431691 is 19613455.

55431691 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a de Polignac number, because none of the positive numbers 2^k-55431691 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (55431641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 565581 + ... + 565678.

It is an arithmetic number, because the mean of its divisors is an integer number (10746970).

Almost surely, 2^55431691 is an apocalyptic number.

55431691 is a deficient number, since it is larger than the sum of its proper divisors (9050129).

55431691 is a wasteful number, since it uses less digits than its factorization.

55431691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1131273 (or 1131266 counting only the distinct ones).

The product of its digits is 16200, while the sum is 34.

The square root of 55431691 is about 7445.2462014362. The cubic root of 55431691 is about 381.2876241289.

The spelling of 55431691 in words is "fifty-five million, four hundred thirty-one thousand, six hundred ninety-one".