681961131 has 6 divisors (see below), whose sum is σ = 985054980. Its totient is φ = 454640748.

The previous prime is 681961127. The next prime is 681961139. The reversal of 681961131 is 131169186.

It is a happy number.

681961131 is a `hidden beast` number, since 6 + 8 + 1 + 9 + 611 + 31 = 666.

It is not a de Polignac number, because 681961131 - 2² = 681961127 is a prime.

It is a super-2 number, since 2×681961131² = 930141968389598322, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (681961139) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 37886721 + ... + 37886738.

It is an arithmetic number, because the mean of its divisors is an integer number (164175830).

Almost surely, 2^681961131 is an apocalyptic number.

681961131 is a deficient number, since it is larger than the sum of its proper divisors (303093849).

681961131 is a wasteful number, since it uses less digits than its factorization.

681961131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75773465 (or 75773462 counting only the distinct ones).

The product of its digits is 7776, while the sum is 36.

The square root of 681961131 is about 26114.3855183307. The cubic root of 681961131 is about 880.2104915724.

The spelling of 681961131 in words is "six hundred eighty-one million, nine hundred sixty-one thousand, one hundred thirty-one".