66993739 has 4 divisors (see below), whose sum is σ = 67110424. Its totient is φ = 66877056.

The previous prime is 66993737. The next prime is 66993763. The reversal of 66993739 is 93739966.

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

It is a cyclic number.

It is not a de Polignac number, because 66993739 - 2¹ = 66993737 is a prime.

It is a super-2 number, since 2×66993739² = 8976322130400242, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66993737) 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, 57477 + ... + 58630.

It is an arithmetic number, because the mean of its divisors is an integer number (16777606).

Almost surely, 2^66993739 is an apocalyptic number.

66993739 is a deficient number, since it is larger than the sum of its proper divisors (116685).

66993739 is a wasteful number, since it uses less digits than its factorization.

66993739 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 116684.

The product of its digits is 1653372, while the sum is 52.

The square root of 66993739 is about 8184.9703114917. The cubic root of 66993739 is about 406.1421582312.

The spelling of 66993739 in words is "sixty-six million, nine hundred ninety-three thousand, seven hundred thirty-nine".