661201764 has 24 divisors (see below), whose sum is σ = 1552047168. Its totient is φ = 219080160.

The previous prime is 661201763. The next prime is 661201813. The reversal of 661201764 is 467102166.

It is not an unprimeable number, because it can be changed into a prime (661201763) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 162967 + ... + 166974.

It is an arithmetic number, because the mean of its divisors is an integer number (64668632).

Almost surely, 2^661201764 is an apocalyptic number.

It is an amenable number.

661201764 is an abundant number, since it is smaller than the sum of its proper divisors (890845404).

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

661201764 is a wasteful number, since it uses less digits than its factorization.

661201764 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 330115 (or 330113 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 33.

The square root of 661201764 is about 25713.8438200126. The cubic root of 661201764 is about 871.1868963584.

The spelling of 661201764 in words is "six hundred sixty-one million, two hundred one thousand, seven hundred sixty-four".