81790907 has 8 divisors (see below), whose sum is σ = 90061632. Its totient is φ = 73659400.

The previous prime is 81790901. The next prime is 81790909. The reversal of 81790907 is 70909718.

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 81790907 - 2²⁶ = 14682043 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81790901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 33569 + ... + 35922.

It is an arithmetic number, because the mean of its divisors is an integer number (11257704).

Almost surely, 2^81790907 is an apocalyptic number.

81790907 is a deficient number, since it is larger than the sum of its proper divisors (8270725).

81790907 is a wasteful number, since it uses less digits than its factorization.

81790907 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69609.

The product of its (nonzero) digits is 31752, while the sum is 41.

The square root of 81790907 is about 9043.8325393607. The cubic root of 81790907 is about 434.0785656998.

The spelling of 81790907 in words is "eighty-one million, seven hundred ninety thousand, nine hundred seven".