66430820 has 12 divisors (see below), whose sum is σ = 139504764. Its totient is φ = 26572320.

The previous prime is 66430811. The next prime is 66430823. The reversal of 66430820 is 2803466.

It can be written as a sum of positive squares in 2 ways, for example, as 36312676 + 30118144 = 6026^2 + 5488^2 .

It is not an unprimeable number, because it can be changed into a prime (66430823) 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, 1660751 + ... + 1660790.

It is an arithmetic number, because the mean of its divisors is an integer number (11625397).

Almost surely, 2^66430820 is an apocalyptic number.

It is an amenable number.

66430820 is an abundant number, since it is smaller than the sum of its proper divisors (73073944).

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

66430820 is a wasteful number, since it uses less digits than its factorization.

66430820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3321550 (or 3321548 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 29.

The square root of 66430820 is about 8150.5104134649. The cubic root of 66430820 is about 405.0014123814.

The spelling of 66430820 in words is "sixty-six million, four hundred thirty thousand, eight hundred twenty".