661394307 has 24 divisors (see below), whose sum is σ = 1043236800. Its totient is φ = 371528976.

The previous prime is 661394297. The next prime is 661394339. The reversal of 661394307 is 703493166.

It is not a de Polignac number, because 661394307 - 2⁴ = 661394291 is a prime.

It is not an unprimeable number, because it can be changed into a prime (661894307) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 29457 + ... + 46802.

It is an arithmetic number, because the mean of its divisors is an integer number (43468200).

Almost surely, 2^661394307 is an apocalyptic number.

661394307 is a deficient number, since it is larger than the sum of its proper divisors (381842493).

661394307 is a wasteful number, since it uses less digits than its factorization.

661394307 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 76335 (or 76328 counting only the distinct ones).

The product of its (nonzero) digits is 81648, while the sum is 39.

The square root of 661394307 is about 25717.5875034965. The cubic root of 661394307 is about 871.2714518190.

The spelling of 661394307 in words is "six hundred sixty-one million, three hundred ninety-four thousand, three hundred seven".