1231212021 has 16 divisors (see below), whose sum is σ = 1768724160. Its totient is φ = 757313280.

The previous prime is 1231211987. The next prime is 1231212049. The reversal of 1231212021 is 1202121321.

It is not a de Polignac number, because 1231212021 - 2²¹ = 1229114869 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1231212071) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 94461 + ... + 106701.

It is an arithmetic number, because the mean of its divisors is an integer number (110545260).

Almost surely, 2^1231212021 is an apocalyptic number.

It is an amenable number.

1231212021 is a deficient number, since it is larger than the sum of its proper divisors (537512139).

1231212021 is a wasteful number, since it uses less digits than its factorization.

1231212021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14836.

The product of its (nonzero) digits is 48, while the sum is 15.

The square root of 1231212021 is about 35088.6309365299. The cubic root of 1231212021 is about 1071.7930808046.

Adding to 1231212021 its reverse (1202121321), we get a palindrome (2433333342).

The spelling of 1231212021 in words is "one billion, two hundred thirty-one million, two hundred twelve thousand, twenty-one".