667963681 has 16 divisors (see below), whose sum is σ = 839680128. Its totient is φ = 520483920.

The previous prime is 667963661. The next prime is 667963691. The reversal of 667963681 is 186369766.

It is not a de Polignac number, because 667963681 - 2⁵ = 667963649 is a prime.

It is a super-2 number, since 2×667963681² = 892350958270139522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (667963661) 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, 26530 + ... + 45163.

It is an arithmetic number, because the mean of its divisors is an integer number (52480008).

Almost surely, 2^667963681 is an apocalyptic number.

It is an amenable number.

667963681 is a deficient number, since it is larger than the sum of its proper divisors (171716447).

667963681 is an equidigital number, since it uses as much as digits as its factorization.

667963681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71733 (or 71711 counting only the distinct ones).

The product of its digits is 1959552, while the sum is 52.

The square root of 667963681 is about 25844.9933449401. The cubic root of 667963681 is about 874.1466209306.

The spelling of 667963681 in words is "six hundred sixty-seven million, nine hundred sixty-three thousand, six hundred eighty-one".