661739521318 has 8 divisors (see below), whose sum is σ = 993248442648. Its totient is φ = 330656707104.

The previous prime is 661739521297. The next prime is 661739521327. The reversal of 661739521318 is 813125937166.

661739521318 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 106522896 + ... + 106529107.

It is an arithmetic number, because the mean of its divisors is an integer number (124156055331).

Almost surely, 2^661739521318 is an apocalyptic number.

661739521318 is a deficient number, since it is larger than the sum of its proper divisors (331508921330).

661739521318 is a wasteful number, since it uses less digits than its factorization.

661739521318 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 213053558.

The product of its digits is 1632960, while the sum is 52.

The spelling of 661739521318 in words is "six hundred sixty-one billion, seven hundred thirty-nine million, five hundred twenty-one thousand, three hundred eighteen".