666402440 has 32 divisors (see below), whose sum is σ = 1635716160. Its totient is φ = 242328000.

The previous prime is 666402419. The next prime is 666402461. The reversal of 666402440 is 44204666.

It is an interprime number because it is at equal distance from previous prime (666402419) and next prime (666402461).

It is a junction number, because it is equal to n+sod(n) for n = 666402397 and 666402406.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 756836 + ... + 757715.

It is an arithmetic number, because the mean of its divisors is an integer number (51116130).

Almost surely, 2^666402440 is an apocalyptic number.

It is an amenable number.

666402440 is an abundant number, since it is smaller than the sum of its proper divisors (969313720).

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

666402440 is a wasteful number, since it uses less digits than its factorization.

666402440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1514573 (or 1514569 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 32.

The square root of 666402440 is about 25814.7717402266. The cubic root of 666402440 is about 873.4650378584.

The spelling of 666402440 in words is "six hundred sixty-six million, four hundred two thousand, four hundred forty".