1231291320 has 64 divisors (see below), whose sum is σ = 4221573120. Its totient is φ = 281437824.

The previous prime is 1231291319. The next prime is 1231291331. The reversal of 1231291320 is 231921321.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 732072 + ... + 733751.

It is an arithmetic number, because the mean of its divisors is an integer number (65962080).

Almost surely, 2^1231291320 is an apocalyptic number.

1231291320 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1231291320 is an abundant number, since it is smaller than the sum of its proper divisors (2990281800).

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

1231291320 is a wasteful number, since it uses less digits than its factorization.

1231291320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1465844 (or 1465840 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 24.

The square root of 1231291320 is about 35089.7608997269. The cubic root of 1231291320 is about 1071.8160907312.

The spelling of 1231291320 in words is "one billion, two hundred thirty-one million, two hundred ninety-one thousand, three hundred twenty".