66315820 has 24 divisors (see below), whose sum is σ = 143756928. Its totient is φ = 25670400.

The previous prime is 66315797. The next prime is 66315841. The reversal of 66315820 is 2851366.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 52861 + ... + 54100.

It is an arithmetic number, because the mean of its divisors is an integer number (5989872).

Almost surely, 2^66315820 is an apocalyptic number.

It is an amenable number.

66315820 is an abundant number, since it is smaller than the sum of its proper divisors (77441108).

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

66315820 is a wasteful number, since it uses less digits than its factorization.

66315820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 107001 (or 106999 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 31.

The square root of 66315820 is about 8143.4525847456. The cubic root of 66315820 is about 404.7675748137.

The spelling of 66315820 in words is "sixty-six million, three hundred fifteen thousand, eight hundred twenty".