665868562740 has 120 divisors (see below), whose sum is σ = 2099678408520. Its totient is φ = 176644841472.

The previous prime is 665868562721. The next prime is 665868562781. The reversal of 665868562740 is 47265868566.

It is a happy number.

665868562740 is a `hidden beast` number, since 6 + 6 + 5 + 8 + 68 + 562 + 7 + 4 + 0 = 666.

665868562740 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 4099328676 + 661769234064 = 64026^2 + 813492^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 752185 + ... + 1377504.

It is an arithmetic number, because the mean of its divisors is an integer number (17497320071).

Almost surely, 2^665868562740 is an apocalyptic number.

665868562740 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

665868562740 is an abundant number, since it is smaller than the sum of its proper divisors (1433809845780).

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

665868562740 is a wasteful number, since it uses less digits than its factorization.

665868562740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2129903 (or 2129892 counting only the distinct ones).

The product of its (nonzero) digits is 116121600, while the sum is 63.

The spelling of 665868562740 in words is "six hundred sixty-five billion, eight hundred sixty-eight million, five hundred sixty-two thousand, seven hundred forty".