665615107400 has 96 divisors (see below), whose sum is σ = 1555901744040. Its totient is φ = 264813864960.

The previous prime is 665615107393. The next prime is 665615107427. The reversal of 665615107400 is 4701516566.

It can be written as a sum of positive squares in 12 ways, for example, as 30989377444 + 634625729956 = 176038^2 + 796634^2 .

It is a super-2 number, since 2×665615107400² (a number of 24 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 28962314 + ... + 28985286.

Almost surely, 2^665615107400 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 665615107400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (777950872020).

665615107400 is an abundant number, since it is smaller than the sum of its proper divisors (890286636640).

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

665615107400 is a wasteful number, since it uses less digits than its factorization.

665615107400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23763 (or 23754 counting only the distinct ones).

The product of its (nonzero) digits is 151200, while the sum is 41.

The spelling of 665615107400 in words is "six hundred sixty-five billion, six hundred fifteen million, one hundred seven thousand, four hundred".