31423210021 has 16 divisors (see below), whose sum is σ = 37807336960. Its totient is φ = 25513230960.

The previous prime is 31423210009. The next prime is 31423210067. The reversal of 31423210021 is 12001232413.

It is a happy number.

It is not a de Polignac number, because 31423210021 - 2¹¹ = 31423207973 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (19).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31423210081) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1739566 + ... + 1757536.

It is an arithmetic number, because the mean of its divisors is an integer number (2362958560).

Almost surely, 2^31423210021 is an apocalyptic number.

It is an amenable number.

31423210021 is a deficient number, since it is larger than the sum of its proper divisors (6384126939).

31423210021 is a wasteful number, since it uses less digits than its factorization.

31423210021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31144.

The product of its (nonzero) digits is 288, while the sum is 19.

Adding to 31423210021 its reverse (12001232413), we get a palindrome (43424442434).

The spelling of 31423210021 in words is "thirty-one billion, four hundred twenty-three million, two hundred ten thousand, twenty-one".