66739731 has 4 divisors (see below), whose sum is σ = 88986312. Its totient is φ = 44493152.

The previous prime is 66739703. The next prime is 66739763. The reversal of 66739731 is 13793766.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66739731 is a prime.

It is a super-2 number, since 2×66739731² = 8908383387904722, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (66739831) 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, 11123286 + ... + 11123291.

It is an arithmetic number, because the mean of its divisors is an integer number (22246578).

Almost surely, 2^66739731 is an apocalyptic number.

66739731 is a deficient number, since it is larger than the sum of its proper divisors (22246581).

66739731 is a wasteful number, since it uses less digits than its factorization.

66739731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22246580.

The product of its digits is 142884, while the sum is 42.

The square root of 66739731 is about 8169.4388424175. The cubic root of 66739731 is about 405.6282096338.

The spelling of 66739731 in words is "sixty-six million, seven hundred thirty-nine thousand, seven hundred thirty-one".