66215378 has 16 divisors (see below), whose sum is σ = 101623704. Its totient is φ = 32348160.

The previous prime is 66215353. The next prime is 66215389. The reversal of 66215378 is 87351266.

It can be written as a sum of positive squares in 4 ways, for example, as 11854249 + 54361129 = 3443^2 + 7373^2 .

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, 17426 + ... + 20882.

Almost surely, 2^66215378 is an apocalyptic number.

66215378 is a deficient number, since it is larger than the sum of its proper divisors (35408326).

66215378 is a wasteful number, since it uses less digits than its factorization.

66215378 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3677.

The product of its digits is 60480, while the sum is 38.

The square root of 66215378 is about 8137.2832075577. The cubic root of 66215378 is about 404.5631177790.

The spelling of 66215378 in words is "sixty-six million, two hundred fifteen thousand, three hundred seventy-eight".