31140947581 has 4 divisors (see below), whose sum is σ = 31160089312. Its totient is φ = 31121805852.

The previous prime is 31140947573. The next prime is 31140947641. The reversal of 31140947581 is 18574904113.

It is a happy number.

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 31140947581 - 2³ = 31140947573 is a prime.

It is a super-2 number, since 2×31140947581² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31140947081) 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, 9568425 + ... + 9571678.

It is an arithmetic number, because the mean of its divisors is an integer number (7790022328).

Almost surely, 2^31140947581 is an apocalyptic number.

It is an amenable number.

31140947581 is a deficient number, since it is larger than the sum of its proper divisors (19141731).

31140947581 is a wasteful number, since it uses less digits than its factorization.

31140947581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19141730.

The product of its (nonzero) digits is 120960, while the sum is 43.

The spelling of 31140947581 in words is "thirty-one billion, one hundred forty million, nine hundred forty-seven thousand, five hundred eighty-one".