31838580721 has 4 divisors (see below), whose sum is σ = 32865631744. Its totient is φ = 30811529700.

The previous prime is 31838580689. The next prime is 31838580803. The reversal of 31838580721 is 12708583813.

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 a cyclic number.

It is not a de Polignac number, because 31838580721 - 2⁵ = 31838580689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31838580121) 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, 513525465 + ... + 513525526.

It is an arithmetic number, because the mean of its divisors is an integer number (8216407936).

Almost surely, 2^31838580721 is an apocalyptic number.

31838580721 is a gapful number since it is divisible by the number (31) formed by its first and last digit.

It is an amenable number.

31838580721 is a deficient number, since it is larger than the sum of its proper divisors (1027051023).

31838580721 is a wasteful number, since it uses less digits than its factorization.

31838580721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1027051022.

The product of its (nonzero) digits is 322560, while the sum is 46.

The spelling of 31838580721 in words is "thirty-one billion, eight hundred thirty-eight million, five hundred eighty thousand, seven hundred twenty-one".