1231020999 has 24 divisors (see below), whose sum is σ = 1921020192. Its totient is φ = 755138880.

The previous prime is 1231020929. The next prime is 1231021009. The reversal of 1231020999 is 9990201321.

It is a happy number.

It is not a de Polignac number, because 1231020999 - 2⁷ = 1231020871 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1231020929) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 20494 + ... + 53684.

It is an arithmetic number, because the mean of its divisors is an integer number (80042508).

Almost surely, 2^1231020999 is an apocalyptic number.

1231020999 is a deficient number, since it is larger than the sum of its proper divisors (689999193).

1231020999 is a wasteful number, since it uses less digits than its factorization.

1231020999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33527 (or 33524 counting only the distinct ones).

The product of its (nonzero) digits is 8748, while the sum is 36.

The square root of 1231020999 is about 35085.9088381646. The cubic root of 1231020999 is about 1071.7376485304.

The spelling of 1231020999 in words is "one billion, two hundred thirty-one million, twenty thousand, nine hundred ninety-nine".