21021310131 has 4 divisors (see below), whose sum is σ = 28028413512. Its totient is φ = 14014206752.

The previous prime is 21021310103. The next prime is 21021310157. The reversal of 21021310131 is 13101312012.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 21021310131 - 2¹⁰ = 21021309107 is a prime.

It is a super-2 number, since 2×21021310131² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21021310131.

It is not an unprimeable number, because it can be changed into a prime (21021310171) 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, 3503551686 + ... + 3503551691.

It is an arithmetic number, because the mean of its divisors is an integer number (7007103378).

Almost surely, 2^21021310131 is an apocalyptic number.

21021310131 is a deficient number, since it is larger than the sum of its proper divisors (7007103381).

21021310131 is an equidigital number, since it uses as much as digits as its factorization.

21021310131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7007103380.

The product of its (nonzero) digits is 36, while the sum is 15.

Adding to 21021310131 its reverse (13101312012), we get a palindrome (34122622143).

The spelling of 21021310131 in words is "twenty-one billion, twenty-one million, three hundred ten thousand, one hundred thirty-one".