81907506331 has 8 divisors (see below), whose sum is σ = 93610678784. Its totient is φ = 70204858920.

The previous prime is 81907506179. The next prime is 81907506341. The reversal of 81907506331 is 13360570918.

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

It is not a de Polignac number, because 81907506331 - 2¹⁵ = 81907473563 is a prime.

It is a super-2 number, since 2×81907506331² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81907506341) 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, 295576 + ... + 501178.

It is an arithmetic number, because the mean of its divisors is an integer number (11701334848).

Almost surely, 2^81907506331 is an apocalyptic number.

81907506331 is a deficient number, since it is larger than the sum of its proper divisors (11703172453).

81907506331 is a wasteful number, since it uses less digits than its factorization.

81907506331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 262521.

The product of its (nonzero) digits is 136080, while the sum is 43.

The spelling of 81907506331 in words is "eighty-one billion, nine hundred seven million, five hundred six thousand, three hundred thirty-one".