66999692 has 24 divisors (see below), whose sum is σ = 120901200. Its totient is φ = 32472576.

The previous prime is 66999689. The next prime is 66999697. The reversal of 66999692 is 29699966.

It is a Smith number, since the sum of its digits (56) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (66999697) 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, 15284 + ... + 19172.

It is an arithmetic number, because the mean of its divisors is an integer number (5037550).

Almost surely, 2^66999692 is an apocalyptic number.

It is an amenable number.

66999692 is a deficient number, since it is larger than the sum of its proper divisors (53901508).

66999692 is a wasteful number, since it uses less digits than its factorization.

66999692 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4025 (or 4023 counting only the distinct ones).

The product of its digits is 2834352, while the sum is 56.

The square root of 66999692 is about 8185.3339577564. Note that the first 3 decimals coincide. The cubic root of 66999692 is about 406.1541876770.

The spelling of 66999692 in words is "sixty-six million, nine hundred ninety-nine thousand, six hundred ninety-two".