21200131031 has 4 divisors (see below), whose sum is σ = 21468487200. Its totient is φ = 20931774864.

The previous prime is 21200131019. The next prime is 21200131033. The reversal of 21200131031 is 13013100212.

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 21200131031 - 2⁶ = 21200130967 is a prime.

It is a super-2 number, since 2×21200131031² (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 = 21200130997 and 21200131015.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21200131033) 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, 134177966 + ... + 134178123.

It is an arithmetic number, because the mean of its divisors is an integer number (5367121800).

Almost surely, 2^21200131031 is an apocalyptic number.

21200131031 is a deficient number, since it is larger than the sum of its proper divisors (268356169).

21200131031 is an equidigital number, since it uses as much as digits as its factorization.

21200131031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 268356168.

The product of its (nonzero) digits is 36, while the sum is 14.

Adding to 21200131031 its reverse (13013100212), we get a palindrome (34213231243).

The spelling of 21200131031 in words is "twenty-one billion, two hundred million, one hundred thirty-one thousand, thirty-one".