669742517 has 8 divisors (see below), whose sum is σ = 672672000. Its totient is φ = 666819504.

The previous prime is 669742483. The next prime is 669742553. The reversal of 669742517 is 715247966.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 669742517 - 2²⁶ = 602633653 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 (669742597) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 361688 + ... + 363534.

It is an arithmetic number, because the mean of its divisors is an integer number (84084000).

Almost surely, 2^669742517 is an apocalyptic number.

It is an amenable number.

669742517 is a deficient number, since it is larger than the sum of its proper divisors (2929483).

669742517 is a wasteful number, since it uses less digits than its factorization.

669742517 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3235.

The product of its digits is 635040, while the sum is 47.

The square root of 669742517 is about 25879.3840150804. The cubic root of 669742517 is about 874.9219051934.

The spelling of 669742517 in words is "six hundred sixty-nine million, seven hundred forty-two thousand, five hundred seventeen".