66411025 has 6 divisors (see below), whose sum is σ = 82349702. Its totient is φ = 53128800.

The previous prime is 66411019. The next prime is 66411029. The reversal of 66411025 is 52011466.

It can be written as a sum of positive squares in 3 ways, for example, as 17172736 + 49238289 = 4144^2 + 7017^2 .

It is not a de Polignac number, because 66411025 - 2³ = 66411017 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (25), and also a Moran number because the ratio is a prime number: 2656441 = 66411025 / (6 + 6 + 4 + 1 + 1 + 0 + 2 + 5).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66411029) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1328196 + ... + 1328245.

Almost surely, 2^66411025 is an apocalyptic number.

It is an amenable number.

66411025 is a deficient number, since it is larger than the sum of its proper divisors (15938677).

66411025 is a wasteful number, since it uses less digits than its factorization.

66411025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2656451 (or 2656446 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 25.

The square root of 66411025 is about 8149.2959818625. The cubic root of 66411025 is about 404.9611810581.

The spelling of 66411025 in words is "sixty-six million, four hundred eleven thousand, twenty-five".