666919344 has 160 divisors (see below), whose sum is σ = 2156084224. Its totient is φ = 172938240.

The previous prime is 666919321. The next prime is 666919387. The reversal of 666919344 is 443919666.

It is a super-2 number, since 2×666919344² = 889562822802780672, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a junction number, because it is equal to n+sod(n) for n = 666919293 and 666919302.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 265197 + ... + 267699.

Almost surely, 2^666919344 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 666919344, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1078042112).

666919344 is an abundant number, since it is smaller than the sum of its proper divisors (1489164880).

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

666919344 is a wasteful number, since it uses less digits than its factorization.

666919344 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2595 (or 2589 counting only the distinct ones).

The product of its digits is 839808, while the sum is 48.

The square root of 666919344 is about 25824.7815866853. The cubic root of 666919344 is about 873.6908177868.

The spelling of 666919344 in words is "six hundred sixty-six million, nine hundred nineteen thousand, three hundred forty-four".