66212240 has 40 divisors (see below), whose sum is σ = 158111160. Its totient is φ = 25767936.

The previous prime is 66212227. The next prime is 66212273. The reversal of 66212240 is 4221266.

It can be written as a sum of positive squares in 4 ways, for example, as 16875664 + 49336576 = 4108^2 + 7024^2 .

It is a tau number, because it is divible by the number of its divisors (40).

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, 8225 + ... + 14144.

It is an arithmetic number, because the mean of its divisors is an integer number (3952779).

Almost surely, 2^66212240 is an apocalyptic number.

It is an amenable number.

66212240 is an abundant number, since it is smaller than the sum of its proper divisors (91898920).

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

66212240 is a wasteful number, since it uses less digits than its factorization.

66212240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22419 (or 22413 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 23.

The square root of 66212240 is about 8137.0903890764. The cubic root of 66212240 is about 404.5567268209.

The spelling of 66212240 in words is "sixty-six million, two hundred twelve thousand, two hundred forty".