291231045 has 80 divisors (see below), whose sum is σ = 610769280. Its totient is φ = 129983616.

The previous prime is 291231023. The next prime is 291231047. The reversal of 291231045 is 540132192.

It is not a de Polignac number, because 291231045 - 2⁵ = 291231013 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (291231047) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 120711 + ... + 123099.

It is an arithmetic number, because the mean of its divisors is an integer number (7634616).

Almost surely, 2^291231045 is an apocalyptic number.

It is an amenable number.

291231045 is an abundant number, since it is smaller than the sum of its proper divisors (319538235).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

291231045 is a wasteful number, since it uses less digits than its factorization.

291231045 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2456 (or 2447 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 27.

The square root of 291231045 is about 17065.4928144487. The cubic root of 291231045 is about 662.8458723236.

The spelling of 291231045 in words is "two hundred ninety-one million, two hundred thirty-one thousand, forty-five".