1231012021 has 4 divisors (see below), whose sum is σ = 1232576992. Its totient is φ = 1229447052.

The previous prime is 1231011997. The next prime is 1231012043. The reversal of 1231012021 is 1202101321.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1231012021 - 2⁵ = 1231011989 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1231011992 and 1231012010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1231012061) 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, 781305 + ... + 782878.

It is an arithmetic number, because the mean of its divisors is an integer number (308144248).

Almost surely, 2^1231012021 is an apocalyptic number.

It is an amenable number.

1231012021 is a deficient number, since it is larger than the sum of its proper divisors (1564971).

1231012021 is an equidigital number, since it uses as much as digits as its factorization.

1231012021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1564970.

The product of its (nonzero) digits is 24, while the sum is 13.

The square root of 1231012021 is about 35085.7808948297. The cubic root of 1231012021 is about 1071.7350430823.

Adding to 1231012021 its reverse (1202101321), we get a palindrome (2433113342).

The spelling of 1231012021 in words is "one billion, two hundred thirty-one million, twelve thousand, twenty-one".