669949513 has 4 divisors (see below), whose sum is σ = 673420948. Its totient is φ = 666478080.

The previous prime is 669949457. The next prime is 669949529. The reversal of 669949513 is 315949966.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 315949966 = 2 ⋅157974983.

It can be written as a sum of positive squares in 2 ways, for example, as 248755984 + 421193529 = 15772^2 + 20523^2 .

It is a cyclic number.

It is not a de Polignac number, because 669949513 - 2⁹ = 669949001 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (669949573) 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, 1735428 + ... + 1735813.

It is an arithmetic number, because the mean of its divisors is an integer number (168355237).

Almost surely, 2^669949513 is an apocalyptic number.

It is an amenable number.

669949513 is a deficient number, since it is larger than the sum of its proper divisors (3471435).

669949513 is a wasteful number, since it uses less digits than its factorization.

669949513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3471434.

The product of its digits is 1574640, while the sum is 52.

The square root of 669949513 is about 25883.3829512295. The cubic root of 669949513 is about 875.0120327053.

The spelling of 669949513 in words is "six hundred sixty-nine million, nine hundred forty-nine thousand, five hundred thirteen".