31666819381 has 8 divisors (see below), whose sum is σ = 33064938720. Its totient is φ = 30289110768.

The previous prime is 31666819369. The next prime is 31666819463. The reversal of 31666819381 is 18391866613.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 31666819381 - 2⁷ = 31666819253 is a prime.

It is a super-2 number, since 2×31666819381² (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 (31666819181) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5099511 + ... + 5105716.

It is an arithmetic number, because the mean of its divisors is an integer number (4133117340).

Almost surely, 2^31666819381 is an apocalyptic number.

It is an amenable number.

31666819381 is a deficient number, since it is larger than the sum of its proper divisors (1398119339).

31666819381 is a wasteful number, since it uses less digits than its factorization.

31666819381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10205363.

The product of its digits is 1119744, while the sum is 52.

The spelling of 31666819381 in words is "thirty-one billion, six hundred sixty-six million, eight hundred nineteen thousand, three hundred eighty-one".