817681901 has 16 divisors (see below), whose sum is σ = 875992320. Its totient is φ = 761354880.

The previous prime is 817681873. The next prime is 817681903. The reversal of 817681901 is 109186718.

It is a cyclic number.

It is not a de Polignac number, because 817681901 - 2²⁶ = 750573037 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (41).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (817681903) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 667976 + ... + 669198.

It is an arithmetic number, because the mean of its divisors is an integer number (54749520).

Almost surely, 2^817681901 is an apocalyptic number.

It is an amenable number.

817681901 is a deficient number, since it is larger than the sum of its proper divisors (58310419).

817681901 is a wasteful number, since it uses less digits than its factorization.

817681901 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1996.

The product of its (nonzero) digits is 24192, while the sum is 41.

The square root of 817681901 is about 28595.1377160524. The cubic root of 817681901 is about 935.1073307541.

The spelling of 817681901 in words is "eight hundred seventeen million, six hundred eighty-one thousand, nine hundred one".