66700491 has 32 divisors (see below), whose sum is σ = 105181440. Its totient is φ = 37065600.

The previous prime is 66700477. The next prime is 66700519. The reversal of 66700491 is 19400766.

It is a happy number.

It is not a de Polignac number, because 66700491 - 2⁷ = 66700363 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is not an unprimeable number, because it can be changed into a prime (66700421) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 77220 + ... + 78078.

It is an arithmetic number, because the mean of its divisors is an integer number (3286920).

Almost surely, 2^66700491 is an apocalyptic number.

66700491 is a deficient number, since it is larger than the sum of its proper divisors (38480949).

66700491 is a wasteful number, since it uses less digits than its factorization.

66700491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1067.

The product of its (nonzero) digits is 9072, while the sum is 33.

The square root of 66700491 is about 8167.0368555554. The cubic root of 66700491 is about 405.5486969198.

The spelling of 66700491 in words is "sixty-six million, seven hundred thousand, four hundred ninety-one".