66938799 has 4 divisors (see below), whose sum is σ = 89251736. Its totient is φ = 44625864.

The previous prime is 66938797. The next prime is 66938801. The reversal of 66938799 is 99783966.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (66938797) and next prime (66938801).

It is not a de Polignac number, because 66938799 - 2¹ = 66938797 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66938797) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11156464 + ... + 11156469.

It is an arithmetic number, because the mean of its divisors is an integer number (22312934).

Almost surely, 2^66938799 is an apocalyptic number.

66938799 is a deficient number, since it is larger than the sum of its proper divisors (22312937).

66938799 is a wasteful number, since it uses less digits than its factorization.

66938799 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22312936.

The product of its digits is 4408992, while the sum is 57.

The square root of 66938799 is about 8181.6134716815. The cubic root of 66938799 is about 406.0311053037.

The spelling of 66938799 in words is "sixty-six million, nine hundred thirty-eight thousand, seven hundred ninety-nine".