54631991 has 2 divisors, whose sum is σ = 54631992. Its totient is φ = 54631990.

The previous prime is 54631981. The next prime is 54632003. The reversal of 54631991 is 19913645.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-54631991 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (54631981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27315995 + 27315996.

It is an arithmetic number, because the mean of its divisors is an integer number (27315996).

Almost surely, 2^54631991 is an apocalyptic number.

54631991 is a deficient number, since it is larger than the sum of its proper divisors (1).

54631991 is an equidigital number, since it uses as much as digits as its factorization.

54631991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 29160, while the sum is 38.

The square root of 54631991 is about 7391.3456826210. The cubic root of 54631991 is about 379.4451528525.

The spelling of 54631991 in words is "fifty-four million, six hundred thirty-one thousand, nine hundred ninety-one".