681922081 has 8 divisors (see below), whose sum is σ = 684885600. Its totient is φ = 678965760.

The previous prime is 681922067. The next prime is 681922091. The reversal of 681922081 is 180229186.

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 681922081 - 2⁵ = 681922049 is a prime.

It is a super-2 number, since 2×681922081² = 930035449110741122, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 681922081.

It is not an unprimeable number, because it can be changed into a prime (681922091) 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, 267310 + ... + 269848.

It is an arithmetic number, because the mean of its divisors is an integer number (85610700).

Almost surely, 2^681922081 is an apocalyptic number.

It is an amenable number.

681922081 is a deficient number, since it is larger than the sum of its proper divisors (2963519).

681922081 is a wasteful number, since it uses less digits than its factorization.

681922081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3599.

The product of its (nonzero) digits is 13824, while the sum is 37.

The square root of 681922081 is about 26113.6378354300. The cubic root of 681922081 is about 880.1936905778.

It can be divided in two parts, 6819 and 22081, that added together give a square (28900 = 170²).

The spelling of 681922081 in words is "six hundred eighty-one million, nine hundred twenty-two thousand, eighty-one".