669702902778 has 128 divisors (see below), whose sum is σ = 1866226521600. Its totient is φ = 173292327936.

The previous prime is 669702902683. The next prime is 669702902801. The reversal of 669702902778 is 877209207966.

669702902778 is a `hidden beast` number, since 6 + 6 + 9 + 70 + 290 + 277 + 8 = 666.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1025263 + ... + 1546146.

It is an arithmetic number, because the mean of its divisors is an integer number (14579894700).

Almost surely, 2^669702902778 is an apocalyptic number.

669702902778 is an abundant number, since it is smaller than the sum of its proper divisors (1196523618822).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

669702902778 is a wasteful number, since it uses less digits than its factorization.

669702902778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2571493 (or 2571487 counting only the distinct ones).

The product of its (nonzero) digits is 32006016, while the sum is 63.

The spelling of 669702902778 in words is "six hundred sixty-nine billion, seven hundred two million, nine hundred two thousand, seven hundred seventy-eight".