21231012021 has 16 divisors (see below), whose sum is σ = 28680388608. Its totient is φ = 13968990000.

The previous prime is 21231011957. The next prime is 21231012041. The reversal of 21231012021 is 12021013212.

It is not a de Polignac number, because 21231012021 - 2⁶ = 21231011957 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21231012041) 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 15 ways as a sum of consecutive naturals, for example, 73105 + ... + 218646.

It is an arithmetic number, because the mean of its divisors is an integer number (1792524288).

Almost surely, 2^21231012021 is an apocalyptic number.

It is an amenable number.

21231012021 is a deficient number, since it is larger than the sum of its proper divisors (7449376587).

21231012021 is a wasteful number, since it uses less digits than its factorization.

21231012021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 292072.

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

Adding to 21231012021 its reverse (12021013212), we get a palindrome (33252025233).

The spelling of 21231012021 in words is "twenty-one billion, two hundred thirty-one million, twelve thousand, twenty-one".