666742072 has 64 divisors (see below), whose sum is σ = 1365811200. Its totient is φ = 304041600.

The previous prime is 666742061. The next prime is 666742073. The reversal of 666742072 is 270247666.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666742073) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 578697 + ... + 579847.

It is an arithmetic number, because the mean of its divisors is an integer number (21340800).

Almost surely, 2^666742072 is an apocalyptic number.

It is an amenable number.

666742072 is an abundant number, since it is smaller than the sum of its proper divisors (699069128).

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

666742072 is a wasteful number, since it uses less digits than its factorization.

666742072 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1316 (or 1312 counting only the distinct ones).

The product of its (nonzero) digits is 169344, while the sum is 40.

The square root of 666742072 is about 25821.3491514289. The cubic root of 666742072 is about 873.6133998077.

The spelling of 666742072 in words is "six hundred sixty-six million, seven hundred forty-two thousand, seventy-two".