669900778 has 8 divisors (see below), whose sum is σ = 1005050340. Its totient is φ = 334884000.

The previous prime is 669900769. The next prime is 669900787. The reversal of 669900778 is 877009966.

It is an interprime number because it is at equal distance from previous prime (669900769) and next prime (669900787).

It can be written as a sum of positive squares in 2 ways, for example, as 668894769 + 1006009 = 25863^2 + 1003^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19443 + ... + 41446.

Almost surely, 2^669900778 is an apocalyptic number.

669900778 is a deficient number, since it is larger than the sum of its proper divisors (335149562).

669900778 is a wasteful number, since it uses less digits than its factorization.

669900778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66392.

The product of its (nonzero) digits is 1143072, while the sum is 52.

The square root of 669900778 is about 25882.4414999822. The cubic root of 669900778 is about 874.9908148151.

The spelling of 669900778 in words is "six hundred sixty-nine million, nine hundred thousand, seven hundred seventy-eight".