66750439 has 16 divisors (see below), whose sum is σ = 83796480. Its totient is φ = 51844320.

The previous prime is 66750427. The next prime is 66750443. The reversal of 66750439 is 93405766.

It is a cyclic number.

It is not a de Polignac number, because 66750439 - 2¹⁷ = 66619367 is a prime.

It is a super-2 number, since 2×66750439² = 8911242213385442, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66750469) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7852 + ... + 13969.

It is an arithmetic number, because the mean of its divisors is an integer number (5237280).

Almost surely, 2^66750439 is an apocalyptic number.

66750439 is a deficient number, since it is larger than the sum of its proper divisors (17046041).

66750439 is a wasteful number, since it uses less digits than its factorization.

66750439 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21870.

The product of its (nonzero) digits is 136080, while the sum is 40.

The square root of 66750439 is about 8170.0941855036. The cubic root of 66750439 is about 405.6499020327.

The spelling of 66750439 in words is "sixty-six million, seven hundred fifty thousand, four hundred thirty-nine".