66021250 has 20 divisors (see below), whose sum is σ = 123752574. Its totient is φ = 26408000.

The previous prime is 66021239. The next prime is 66021253. The reversal of 66021250 is 5212066.

It can be written as a sum of positive squares in 5 ways, for example, as 4853209 + 61168041 = 2203^2 + 7821^2 .

It is not an unprimeable number, because it can be changed into a prime (66021253) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 25159 + ... + 27658.

Almost surely, 2^66021250 is an apocalyptic number.

66021250 is a deficient number, since it is larger than the sum of its proper divisors (57731324).

66021250 is an equidigital number, since it uses as much as digits as its factorization.

66021250 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52839 (or 52824 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 22.

The square root of 66021250 is about 8125.3461464728. The cubic root of 66021250 is about 404.1673693024.

The spelling of 66021250 in words is "sixty-six million, twenty-one thousand, two hundred fifty".