31403738521 has 3 divisors (see below), whose sum is σ = 31403915733. Its totient is φ = 31403561310.

The previous prime is 31403738519. The next prime is 31403738609. The reversal of 31403738521 is 12583730413.

The square root of 31403738521 is 177211.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is not a de Polignac number, because 31403738521 - 2¹ = 31403738519 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31403738501) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 88606 + ... + 265816.

It is an arithmetic number, because the mean of its divisors is an integer number (10467971911).

Almost surely, 2^31403738521 is an apocalyptic number.

31403738521 is the 177211-st square number.

31403738521 is the 88606-th centered octagonal number.

It is an amenable number.

31403738521 is a deficient number, since it is larger than the sum of its proper divisors (177212).

31403738521 is an frugal number, since it uses more digits than its factorization.

31403738521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 354422 (or 177211 counting only the distinct ones).

The product of its (nonzero) digits is 60480, while the sum is 37.

The spelling of 31403738521 in words is "thirty-one billion, four hundred three million, seven hundred thirty-eight thousand, five hundred twenty-one".