1231030021 has 16 divisors (see below), whose sum is σ = 1360679040. Its totient is φ = 1106763840.

The previous prime is 1231030013. The next prime is 1231030037. The reversal of 1231030021 is 1200301321.

It is not a de Polignac number, because 1231030021 - 2³ = 1231030013 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (13).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1231029983 and 1231030010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1231030421) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 68575 + ... + 84643.

It is an arithmetic number, because the mean of its divisors is an integer number (85042440).

Almost surely, 2^1231030021 is an apocalyptic number.

It is an amenable number.

1231030021 is a deficient number, since it is larger than the sum of its proper divisors (129649019).

1231030021 is a wasteful number, since it uses less digits than its factorization.

1231030021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16236.

The product of its (nonzero) digits is 36, while the sum is 13.

The square root of 1231030021 is about 35086.0374080631. The cubic root of 1231030021 is about 1071.7402667347.

Adding to 1231030021 its reverse (1200301321), we get a palindrome (2431331342).

The spelling of 1231030021 in words is "one billion, two hundred thirty-one million, thirty thousand, twenty-one".