81617473 has 8 divisors (see below), whose sum is σ = 94858560. Its totient is φ = 68771760.

The previous prime is 81617467. The next prime is 81617477. The reversal of 81617473 is 37471618.

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 81617473 - 2⁵ = 81617441 is a prime.

It is a super-2 number, since 2×81617473² = 13322823797811458, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81617477) 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, 98398 + ... + 99223.

It is an arithmetic number, because the mean of its divisors is an integer number (11857320).

Almost surely, 2^81617473 is an apocalyptic number.

It is an amenable number.

81617473 is a deficient number, since it is larger than the sum of its proper divisors (13241087).

81617473 is a wasteful number, since it uses less digits than its factorization.

81617473 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 197687.

The product of its digits is 28224, while the sum is 37.

The square root of 81617473 is about 9034.2389275467. The cubic root of 81617473 is about 433.7715337830.

The spelling of 81617473 in words is "eighty-one million, six hundred seventeen thousand, four hundred seventy-three".