66491290 has 16 divisors (see below), whose sum is σ = 119784168. Its totient is φ = 26574336.

The previous prime is 66491261. The next prime is 66491303. The reversal of 66491290 is 9219466.

It can be written as a sum of positive squares in 4 ways, for example, as 22838841 + 43652449 = 4779^2 + 6607^2 .

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, 15634 + ... + 19426.

Almost surely, 2^66491290 is an apocalyptic number.

66491290 is a deficient number, since it is larger than the sum of its proper divisors (53292878).

66491290 is a wasteful number, since it uses less digits than its factorization.

66491290 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5553.

The product of its (nonzero) digits is 23328, while the sum is 37.

The square root of 66491290 is about 8154.2191532973. The cubic root of 66491290 is about 405.1242620275.

The spelling of 66491290 in words is "sixty-six million, four hundred ninety-one thousand, two hundred ninety".