669712681 has 8 divisors (see below), whose sum is σ = 730786464. Its totient is φ = 608670720.

The previous prime is 669712669. The next prime is 669712699. The reversal of 669712681 is 186217966.

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 669712681 - 2⁷ = 669712553 is a prime.

It is a super-2 number, since 2×669712681² = 897030150184415522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (669712661) 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, 65961 + ... + 75433.

It is an arithmetic number, because the mean of its divisors is an integer number (91348308).

Almost surely, 2^669712681 is an apocalyptic number.

It is an amenable number.

669712681 is a deficient number, since it is larger than the sum of its proper divisors (61073783).

669712681 is a wasteful number, since it uses less digits than its factorization.

669712681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15911.

The product of its digits is 217728, while the sum is 46.

The square root of 669712681 is about 25878.8075652647. The cubic root of 669712681 is about 874.9089128583.

The spelling of 669712681 in words is "six hundred sixty-nine million, seven hundred twelve thousand, six hundred eighty-one".