66144638 has 16 divisors (see below), whose sum is σ = 117049344. Its totient is φ = 27433080.

The previous prime is 66144623. The next prime is 66144653. The reversal of 66144638 is 83644166.

It is an interprime number because it is at equal distance from previous prime (66144623) and next prime (66144653).

It is a super-2 number, since 2×66144638² = 8750226272302088, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

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, 75770 + ... + 76637.

It is an arithmetic number, because the mean of its divisors is an integer number (7315584).

Almost surely, 2^66144638 is an apocalyptic number.

66144638 is a deficient number, since it is larger than the sum of its proper divisors (50904706).

66144638 is a wasteful number, since it uses less digits than its factorization.

66144638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 152447.

The product of its digits is 82944, while the sum is 38.

The square root of 66144638 is about 8132.9353864395. The cubic root of 66144638 is about 404.4189972171.

The spelling of 66144638 in words is "sixty-six million, one hundred forty-four thousand, six hundred thirty-eight".