661591294 has 32 divisors (see below), whose sum is σ = 1223199936. Its totient is φ = 261342720.

The previous prime is 661591283. The next prime is 661591303. The reversal of 661591294 is 492195166.

It is a self number, because there is not a number n which added to its sum of digits gives 661591294.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 142774 + ... + 147334.

It is an arithmetic number, because the mean of its divisors is an integer number (38224998).

Almost surely, 2^661591294 is an apocalyptic number.

661591294 is a deficient number, since it is larger than the sum of its proper divisors (561608642).

661591294 is a wasteful number, since it uses less digits than its factorization.

661591294 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5380.

The product of its digits is 116640, while the sum is 43.

The square root of 661591294 is about 25721.4170293940. The cubic root of 661591294 is about 871.3579418857.

The spelling of 661591294 in words is "six hundred sixty-one million, five hundred ninety-one thousand, two hundred ninety-four".