31443870421 has 4 divisors (see below), whose sum is σ = 31617593644. Its totient is φ = 31270147200.

The previous prime is 31443870391. The next prime is 31443870427. The reversal of 31443870421 is 12407834413.

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

It can be written as a sum of positive squares in 2 ways, for example, as 2002115025 + 29441755396 = 44745^2 + 171586^2 .

It is a cyclic number.

It is not a de Polignac number, because 31443870421 - 2⁵ = 31443870389 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31443870427) 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, 86861340 + ... + 86861701.

It is an arithmetic number, because the mean of its divisors is an integer number (7904398411).

Almost surely, 2^31443870421 is an apocalyptic number.

It is an amenable number.

31443870421 is a deficient number, since it is larger than the sum of its proper divisors (173723223).

31443870421 is a wasteful number, since it uses less digits than its factorization.

31443870421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 173723222.

The product of its (nonzero) digits is 64512, while the sum is 37.

The spelling of 31443870421 in words is "thirty-one billion, four hundred forty-three million, eight hundred seventy thousand, four hundred twenty-one".