66604840 has 16 divisors (see below), whose sum is σ = 149860980. Its totient is φ = 26641920.

The previous prime is 66604829. The next prime is 66604843. The reversal of 66604840 is 4840666.

It can be written as a sum of positive squares in 2 ways, for example, as 61685316 + 4919524 = 7854^2 + 2218^2 .

It is a super-2 number, since 2×66604840² = 8872409422851200, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 66604796 and 66604805.

It is not an unprimeable number, because it can be changed into a prime (66604843) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 832521 + ... + 832600.

Almost surely, 2^66604840 is an apocalyptic number.

It is an amenable number.

66604840 is an abundant number, since it is smaller than the sum of its proper divisors (83256140).

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

66604840 is a wasteful number, since it uses less digits than its factorization.

66604840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1665132 (or 1665128 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 34.

The square root of 66604840 is about 8161.1788364182. The cubic root of 66604840 is about 405.3547468441.

The spelling of 66604840 in words is "sixty-six million, six hundred four thousand, eight hundred forty".