66213776 has 20 divisors (see below), whose sum is σ = 135836172. Its totient is φ = 31159296.

The previous prime is 66213769. The next prime is 66213781. The reversal of 66213776 is 67731266.

It can be written as a sum of positive squares in 2 ways, for example, as 59660176 + 6553600 = 7724^2 + 2560^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 121445 + ... + 121988.

Almost surely, 2^66213776 is an apocalyptic number.

It is an amenable number.

66213776 is an abundant number, since it is smaller than the sum of its proper divisors (69622396).

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

66213776 is a wasteful number, since it uses less digits than its factorization.

66213776 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 243458 (or 243452 counting only the distinct ones).

The product of its digits is 63504, while the sum is 38.

The square root of 66213776 is about 8137.1847711601. The cubic root of 66213776 is about 404.5598551163.

The spelling of 66213776 in words is "sixty-six million, two hundred thirteen thousand, seven hundred seventy-six".