661394707 has 6 divisors (see below), whose sum is σ = 702589148. Its totient is φ = 622488864.

The previous prime is 661394687. The next prime is 661394711. The reversal of 661394707 is 707493166.

It is not a de Polignac number, because 661394707 - 2¹¹ = 661392659 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (661394717) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1143993 + ... + 1144570.

Almost surely, 2^661394707 is an apocalyptic number.

661394707 is a deficient number, since it is larger than the sum of its proper divisors (41194441).

661394707 is a wasteful number, since it uses less digits than its factorization.

661394707 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2288597 (or 2288580 counting only the distinct ones).

The product of its (nonzero) digits is 190512, while the sum is 43.

The square root of 661394707 is about 25717.5952802746. The cubic root of 661394707 is about 871.2716274623.

The spelling of 661394707 in words is "six hundred sixty-one million, three hundred ninety-four thousand, seven hundred seven".