66138963 has 12 divisors (see below), whose sum is σ = 96931464. Its totient is φ = 40084000.

The previous prime is 66138931. The next prime is 66138971. The reversal of 66138963 is 36983166.

It is not a de Polignac number, because 66138963 - 2⁵ = 66138931 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66138913) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 90738 + ... + 91463.

It is an arithmetic number, because the mean of its divisors is an integer number (8077622).

Almost surely, 2^66138963 is an apocalyptic number.

66138963 is a deficient number, since it is larger than the sum of its proper divisors (30792501).

66138963 is a wasteful number, since it uses less digits than its factorization.

66138963 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 182226 (or 182215 counting only the distinct ones).

The product of its digits is 139968, while the sum is 42.

The square root of 66138963 is about 8132.5864889345. The cubic root of 66138963 is about 404.4074309308.

It can be divided in two parts, 6613 and 8963, that added together give a triangular number (15576 = T₁₇₆).

The spelling of 66138963 in words is "sixty-six million, one hundred thirty-eight thousand, nine hundred sixty-three".