31981415981 has 8 divisors (see below), whose sum is σ = 33374453760. Its totient is φ = 30588590032.

The previous prime is 31981415959. The next prime is 31981415987. The reversal of 31981415981 is 18951418913.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31981415981 is a prime.

It is a super-2 number, since 2×31981415981² (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 (31981415987) 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, 307991 + ... + 398523.

It is an arithmetic number, because the mean of its divisors is an integer number (4171806720).

Almost surely, 2^31981415981 is an apocalyptic number.

It is an amenable number.

31981415981 is a deficient number, since it is larger than the sum of its proper divisors (1393037779).

31981415981 is a wasteful number, since it uses less digits than its factorization.

31981415981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 105915.

The product of its digits is 311040, while the sum is 50.

The spelling of 31981415981 in words is "thirty-one billion, nine hundred eighty-one million, four hundred fifteen thousand, nine hundred eighty-one".