681121690 has 16 divisors (see below), whose sum is σ = 1290546720. Its totient is φ = 258109200.

The previous prime is 681121687. The next prime is 681121699. The reversal of 681121690 is 96121186.

It is a super-2 number, since 2×681121690² = 927853513176912200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (681121699) 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, 1792236 + ... + 1792615.

It is an arithmetic number, because the mean of its divisors is an integer number (80659170).

Almost surely, 2^681121690 is an apocalyptic number.

681121690 is a deficient number, since it is larger than the sum of its proper divisors (609425030).

681121690 is a wasteful number, since it uses less digits than its factorization.

681121690 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3584877.

The product of its (nonzero) digits is 5184, while the sum is 34.

The square root of 681121690 is about 26098.3081827156. The cubic root of 681121690 is about 879.8491864486.

The spelling of 681121690 in words is "six hundred eighty-one million, one hundred twenty-one thousand, six hundred ninety".