45231991 has 4 divisors (see below), whose sum is σ = 51693712. Its totient is φ = 38770272.

The previous prime is 45231919. The next prime is 45231997. The reversal of 45231991 is 19913254.

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 45231991 - 2⁷ = 45231863 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (45231997) 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, 3230850 + ... + 3230863.

It is an arithmetic number, because the mean of its divisors is an integer number (12923428).

Almost surely, 2^45231991 is an apocalyptic number.

45231991 is a deficient number, since it is larger than the sum of its proper divisors (6461721).

45231991 is an equidigital number, since it uses as much as digits as its factorization.

45231991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6461720.

The product of its digits is 9720, while the sum is 34.

The square root of 45231991 is about 6725.4732918955. The cubic root of 45231991 is about 356.2995180578.

The spelling of 45231991 in words is "forty-five million, two hundred thirty-one thousand, nine hundred ninety-one".