21021332131 has 4 divisors (see below), whose sum is σ = 21068784792. Its totient is φ = 20973879472.

The previous prime is 21021332117. The next prime is 21021332141. The reversal of 21021332131 is 13123312012.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21021332131 is a prime.

It is a super-2 number, since 2×21021332131² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21021332099 and 21021332108.

It is not an unprimeable number, because it can be changed into a prime (21021332141) 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, 23725666 + ... + 23726551.

It is an arithmetic number, because the mean of its divisors is an integer number (5267196198).

Almost surely, 2^21021332131 is an apocalyptic number.

21021332131 is a deficient number, since it is larger than the sum of its proper divisors (47452661).

21021332131 is an equidigital number, since it uses as much as digits as its factorization.

21021332131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47452660.

The product of its (nonzero) digits is 216, while the sum is 19.

Adding to 21021332131 its reverse (13123312012), we get a palindrome (34144644143).

The spelling of 21021332131 in words is "twenty-one billion, twenty-one million, three hundred thirty-two thousand, one hundred thirty-one".