669157720 has 192 divisors, whose sum is σ = 1959824160. Its totient is φ = 203212800.

The previous prime is 669157711. The next prime is 669157733. The reversal of 669157720 is 27751966.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 883582 + ... + 884338.

Almost surely, 2^669157720 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 669157720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (979912080).

669157720 is an abundant number, since it is smaller than the sum of its proper divisors (1290666440).

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

669157720 is a wasteful number, since it uses less digits than its factorization.

669157720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 834 (or 823 counting only the distinct ones).

The product of its (nonzero) digits is 158760, while the sum is 43.

The square root of 669157720 is about 25868.0830368236. The cubic root of 669157720 is about 874.6671800895.

The spelling of 669157720 in words is "six hundred sixty-nine million, one hundred fifty-seven thousand, seven hundred twenty".