669417840 has 480 divisors, whose sum is σ = 2934562176. Its totient is φ = 132710400.

The previous prime is 669417809. The next prime is 669417869. The reversal of 669417840 is 48714966.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 1113540 + ... + 1114140.

Almost surely, 2^669417840 is an apocalyptic number.

669417840 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 669417840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1467281088).

669417840 is an abundant number, since it is smaller than the sum of its proper divisors (2265144336).

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

669417840 is a wasteful number, since it uses less digits than its factorization.

669417840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 657 (or 648 counting only the distinct ones).

The product of its (nonzero) digits is 290304, while the sum is 45.

The square root of 669417840 is about 25873.1103657832. The cubic root of 669417840 is about 874.7805011325.

The spelling of 669417840 in words is "six hundred sixty-nine million, four hundred seventeen thousand, eight hundred forty".