661793394507 has 48 divisors (see below), whose sum is σ = 1036325751552. Its totient is φ = 374546652480.

The previous prime is 661793394499. The next prime is 661793394539. The reversal of 661793394507 is 705493397166.

It is a happy number.

It is not a de Polignac number, because 661793394507 - 2³ = 661793394499 is a prime.

It is not an unprimeable number, because it can be changed into a prime (661793394007) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 7131468 + ... + 7223670.

It is an arithmetic number, because the mean of its divisors is an integer number (21590119824).

Almost surely, 2^661793394507 is an apocalyptic number.

661793394507 is a deficient number, since it is larger than the sum of its proper divisors (374532357045).

661793394507 is a wasteful number, since it uses less digits than its factorization.

661793394507 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 92688 (or 92681 counting only the distinct ones).

The product of its (nonzero) digits is 25719120, while the sum is 60.

The spelling of 661793394507 in words is "six hundred sixty-one billion, seven hundred ninety-three million, three hundred ninety-four thousand, five hundred seven".