1665908856 has 48 divisors (see below), whose sum is σ = 4678947000. Its totient is φ = 555302304.

The previous prime is 1665908813. The next prime is 1665908899. The reversal of 1665908856 is 6588095661.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (1665908813) and next prime (1665908899).

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 11 ways as a sum of consecutive naturals, for example, 426531 + ... + 430418.

Almost surely, 2^1665908856 is an apocalyptic number.

It is an amenable number.

1665908856 is an abundant number, since it is smaller than the sum of its proper divisors (3013038144).

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

1665908856 is an equidigital number, since it uses as much as digits as its factorization.

1665908856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 856970 (or 856954 counting only the distinct ones).

The product of its (nonzero) digits is 3110400, while the sum is 54.

The square root of 1665908856 is about 40815.5467438573. The cubic root of 1665908856 is about 1185.4513774755.

The spelling of 1665908856 in words is "one billion, six hundred sixty-five million, nine hundred eight thousand, eight hundred fifty-six".