81617967 has 24 divisors (see below), whose sum is σ = 122579184. Its totient is φ = 52285824.

The previous prime is 81617959. The next prime is 81617971. The reversal of 81617967 is 76971618.

It is not a de Polignac number, because 81617967 - 2³ = 81617959 is a prime.

It is a super-2 number, since 2×81617967² = 13322985074426178, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81617267) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 26163 + ... + 29115.

It is an arithmetic number, because the mean of its divisors is an integer number (5107466).

Almost surely, 2^81617967 is an apocalyptic number.

81617967 is a deficient number, since it is larger than the sum of its proper divisors (40961217).

81617967 is a wasteful number, since it uses less digits than its factorization.

81617967 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3079 (or 3076 counting only the distinct ones).

The product of its digits is 127008, while the sum is 45.

The square root of 81617967 is about 9034.2662679379. The cubic root of 81617967 is about 433.7724089334.

The spelling of 81617967 in words is "eighty-one million, six hundred seventeen thousand, nine hundred sixty-seven".