31290219021 has 4 divisors (see below), whose sum is σ = 41720292032. Its totient is φ = 20860146012.

The previous prime is 31290218987. The next prime is 31290219043. The reversal of 31290219021 is 12091209213.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 31290219021 - 2¹⁷ = 31290087949 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 31290219021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31290209021) 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, 5215036501 + ... + 5215036506.

It is an arithmetic number, because the mean of its divisors is an integer number (10430073008).

Almost surely, 2^31290219021 is an apocalyptic number.

It is an amenable number.

31290219021 is a deficient number, since it is larger than the sum of its proper divisors (10430073011).

31290219021 is a wasteful number, since it uses less digits than its factorization.

31290219021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10430073010.

The product of its (nonzero) digits is 1944, while the sum is 30.

The spelling of 31290219021 in words is "thirty-one billion, two hundred ninety million, two hundred nineteen thousand, twenty-one".