666687456 has 48 divisors (see below), whose sum is σ = 1944507600. Its totient is φ = 222228864.

The previous prime is 666687431. The next prime is 666687479. The reversal of 666687456 is 654786666.

It is a tau number, because it is divible by the number of its divisors (48).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

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, 384951 + ... + 386678.

It is an arithmetic number, because the mean of its divisors is an integer number (40510575).

Almost surely, 2^666687456 is an apocalyptic number.

It is an amenable number.

666687456 is an abundant number, since it is smaller than the sum of its proper divisors (1277820144).

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

666687456 is a wasteful number, since it uses less digits than its factorization.

666687456 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 771648 (or 771634 counting only the distinct ones).

The product of its digits is 8709120, while the sum is 54.

The square root of 666687456 is about 25820.2915552865. The cubic root of 666687456 is about 873.5895452196.

The spelling of 666687456 in words is "six hundred sixty-six million, six hundred eighty-seven thousand, four hundred fifty-six".