669921899 has 2 divisors, whose sum is σ = 669921900. Its totient is φ = 669921898.

The previous prime is 669921881. The next prime is 669921911. The reversal of 669921899 is 998129966.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 669921899 - 2²⁰ = 668873323 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (669921809) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 334960949 + 334960950.

It is an arithmetic number, because the mean of its divisors is an integer number (334960950).

Almost surely, 2^669921899 is an apocalyptic number.

669921899 is a deficient number, since it is larger than the sum of its proper divisors (1).

669921899 is an equidigital number, since it uses as much as digits as its factorization.

669921899 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3779136, while the sum is 59.

The square root of 669921899 is about 25882.8495146883. The cubic root of 669921899 is about 875.0000104490. Note that the first 4 decimals are identical.

The spelling of 669921899 in words is "six hundred sixty-nine million, nine hundred twenty-one thousand, eight hundred ninety-nine".