681990177 has 8 divisors (see below), whose sum is σ = 991985760. Its totient is φ = 413327360.

The previous prime is 681990149. The next prime is 681990209. The reversal of 681990177 is 771099186.

It is a happy number.

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 681990177 - 2⁸ = 681989921 is a prime.

It is a super-2 number, since 2×681990177² = 930221203048982658, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (681990107) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10333152 + ... + 10333217.

It is an arithmetic number, because the mean of its divisors is an integer number (123998220).

Almost surely, 2^681990177 is an apocalyptic number.

It is an amenable number.

681990177 is a deficient number, since it is larger than the sum of its proper divisors (309995583).

681990177 is a wasteful number, since it uses less digits than its factorization.

681990177 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20666383.

The product of its (nonzero) digits is 190512, while the sum is 48.

The square root of 681990177 is about 26114.9416426689. The cubic root of 681990177 is about 880.2229879987. Note that the first 3 decimals are identical.

The spelling of 681990177 in words is "six hundred eighty-one million, nine hundred ninety thousand, one hundred seventy-seven".