31231421021 has 8 divisors (see below), whose sum is σ = 33629048640. Its totient is φ = 28896069568.

The previous prime is 31231420967. The next prime is 31231421029. The reversal of 31231421021 is 12012413213.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 31231421021 - 2³⁰ = 30157679197 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31231420984 and 31231421002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31231421029) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15568001 + ... + 15570006.

It is an arithmetic number, because the mean of its divisors is an integer number (4203631080).

Almost surely, 2^31231421021 is an apocalyptic number.

It is an amenable number.

31231421021 is a deficient number, since it is larger than the sum of its proper divisors (2397627619).

31231421021 is a wasteful number, since it uses less digits than its factorization.

31231421021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31138083.

The product of its (nonzero) digits is 288, while the sum is 20.

Adding to 31231421021 its reverse (12012413213), we get a palindrome (43243834234).

The spelling of 31231421021 in words is "thirty-one billion, two hundred thirty-one million, four hundred twenty-one thousand, twenty-one".