31413251721 has 4 divisors (see below), whose sum is σ = 41884335632. Its totient is φ = 20942167812.

The previous prime is 31413251717. The next prime is 31413251747. The reversal of 31413251721 is 12715231413.

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 31413251721 - 2² = 31413251717 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31413251761) 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, 5235541951 + ... + 5235541956.

It is an arithmetic number, because the mean of its divisors is an integer number (10471083908).

Almost surely, 2^31413251721 is an apocalyptic number.

It is an amenable number.

31413251721 is a deficient number, since it is larger than the sum of its proper divisors (10471083911).

31413251721 is a wasteful number, since it uses less digits than its factorization.

31413251721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10471083910.

The product of its digits is 5040, while the sum is 30.

The spelling of 31413251721 in words is "thirty-one billion, four hundred thirteen million, two hundred fifty-one thousand, seven hundred twenty-one".