66491633 has 16 divisors (see below), whose sum is σ = 73256400. Its totient is φ = 59980800.

The previous prime is 66491609. The next prime is 66491639. The reversal of 66491633 is 33619466.

It can be written as a sum of positive squares in 8 ways, for example, as 4129024 + 62362609 = 2032^2 + 7897^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66491633 is a prime.

It is a super-2 number, since 2×66491633² = 8842274518013378, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (66491639) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 116573 + ... + 117141.

It is an arithmetic number, because the mean of its divisors is an integer number (4578525).

Almost surely, 2^66491633 is an apocalyptic number.

It is an amenable number.

66491633 is a deficient number, since it is larger than the sum of its proper divisors (6764767).

66491633 is a wasteful number, since it uses less digits than its factorization.

66491633 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 772.

The product of its digits is 69984, while the sum is 38.

The square root of 66491633 is about 8154.2401853269. The cubic root of 66491633 is about 405.1249586470.

The spelling of 66491633 in words is "sixty-six million, four hundred ninety-one thousand, six hundred thirty-three".