31947281161 has 8 divisors (see below), whose sum is σ = 34613197344. Its totient is φ = 29368772160.

The previous prime is 31947281143. The next prime is 31947281203. The reversal of 31947281161 is 16118274913.

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 31947281161 - 2⁷ = 31947281033 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (43).

It is not an unprimeable number, because it can be changed into a prime (31947281461) 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, 21851035 + ... + 21852496.

It is an arithmetic number, because the mean of its divisors is an integer number (4326649668).

Almost surely, 2^31947281161 is an apocalyptic number.

It is an amenable number.

31947281161 is a deficient number, since it is larger than the sum of its proper divisors (2665916183).

31947281161 is a wasteful number, since it uses less digits than its factorization.

31947281161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43703591.

The product of its digits is 72576, while the sum is 43.

The spelling of 31947281161 in words is "thirty-one billion, nine hundred forty-seven million, two hundred eighty-one thousand, one hundred sixty-one".