66946820 has 12 divisors (see below), whose sum is σ = 140588364. Its totient is φ = 26778720.

The previous prime is 66946811. The next prime is 66946849. The reversal of 66946820 is 2864966.

It can be written as a sum of positive squares in 2 ways, for example, as 41886784 + 25060036 = 6472^2 + 5006^2 .

It is a super-2 number, since 2×66946820² = 8963753416224800, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1673651 + ... + 1673690.

It is an arithmetic number, because the mean of its divisors is an integer number (11715697).

Almost surely, 2^66946820 is an apocalyptic number.

It is an amenable number.

66946820 is an abundant number, since it is smaller than the sum of its proper divisors (73641544).

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

66946820 is a wasteful number, since it uses less digits than its factorization.

66946820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3347350 (or 3347348 counting only the distinct ones).

The product of its (nonzero) digits is 124416, while the sum is 41.

The square root of 66946820 is about 8182.1036414849. The cubic root of 66946820 is about 406.0473223331.

The spelling of 66946820 in words is "sixty-six million, nine hundred forty-six thousand, eight hundred twenty".