665695744 has 80 divisors (see below), whose sum is σ = 1527821856. Its totient is φ = 283852800.

The previous prime is 665695729. The next prime is 665695753. The reversal of 665695744 is 447596566.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 665695691 and 665695700.

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, 1006774 + ... + 1007434.

Almost surely, 2^665695744 is an apocalyptic number.

665695744 is a gapful number since it is divisible by the number (64) 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 665695744, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (763910928).

665695744 is an abundant number, since it is smaller than the sum of its proper divisors (862126112).

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

665695744 is an equidigital number, since it uses as much as digits as its factorization.

665695744 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 967 (or 951 counting only the distinct ones).

The product of its digits is 5443200, while the sum is 52.

The square root of 665695744 is about 25801.0802874608. The cubic root of 665695744 is about 873.1561691533.

It can be divided in two parts, 6656 and 95744, that added together give a square (102400 = 320²).

The spelling of 665695744 in words is "six hundred sixty-five million, six hundred ninety-five thousand, seven hundred forty-four".