21010531431 has 4 divisors (see below), whose sum is σ = 28014041912. Its totient is φ = 14007020952.

The previous prime is 21010531429. The next prime is 21010531453. The reversal of 21010531431 is 13413501012.

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

It is not a de Polignac number, because 21010531431 - 2¹ = 21010531429 is a prime.

It is a super-2 number, since 2×21010531431² (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 = 21010531398 and 21010531407.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21010531471) 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, 3501755236 + ... + 3501755241.

It is an arithmetic number, because the mean of its divisors is an integer number (7003510478).

Almost surely, 2^21010531431 is an apocalyptic number.

21010531431 is a deficient number, since it is larger than the sum of its proper divisors (7003510481).

21010531431 is an equidigital number, since it uses as much as digits as its factorization.

21010531431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7003510480.

The product of its (nonzero) digits is 360, while the sum is 21.

The spelling of 21010531431 in words is "twenty-one billion, ten million, five hundred thirty-one thousand, four hundred thirty-one".