669523651 has 4 divisors (see below), whose sum is σ = 669636592. Its totient is φ = 669410712.

The previous prime is 669523649. The next prime is 669523693. The reversal of 669523651 is 156325966.

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 669523651 - 2¹ = 669523649 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 669523598 and 669523607.

It is not an unprimeable number, because it can be changed into a prime (669523051) 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, 47055 + ... + 59608.

It is an arithmetic number, because the mean of its divisors is an integer number (167409148).

Almost surely, 2^669523651 is an apocalyptic number.

669523651 is a deficient number, since it is larger than the sum of its proper divisors (112941).

669523651 is a wasteful number, since it uses less digits than its factorization.

669523651 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 112940.

The product of its digits is 291600, while the sum is 43.

The square root of 669523651 is about 25875.1550913226. The cubic root of 669523651 is about 874.8265891997.

The spelling of 669523651 in words is "six hundred sixty-nine million, five hundred twenty-three thousand, six hundred fifty-one".