66899670 has 32 divisors (see below), whose sum is σ = 161202528. Its totient is φ = 17768448.

The previous prime is 66899669. The next prime is 66899671. The reversal of 66899670 is 7699866.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (66899669) and next prime (66899671).

It is a super-2 number, since 2×66899670² = 8951131692217800, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66899671) 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, 3372 + ... + 12048.

It is an arithmetic number, because the mean of its divisors is an integer number (5037579).

Almost surely, 2^66899670 is an apocalyptic number.

66899670 is an abundant number, since it is smaller than the sum of its proper divisors (94302858).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66899670 is a wasteful number, since it uses less digits than its factorization.

66899670 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8944.

The product of its (nonzero) digits is 979776, while the sum is 51.

The square root of 66899670 is about 8179.2218456281. The cubic root of 66899670 is about 405.9519748738.

The spelling of 66899670 in words is "sixty-six million, eight hundred ninety-nine thousand, six hundred seventy".