661358044 has 12 divisors (see below), whose sum is σ = 1185605568. Its totient is φ = 322613600.

The previous prime is 661358029. The next prime is 661358053. The reversal of 661358044 is 440853166.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 661357994 and 661358012.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2016172 + ... + 2016499.

It is an arithmetic number, because the mean of its divisors is an integer number (98800464).

Almost surely, 2^661358044 is an apocalyptic number.

It is an amenable number.

661358044 is a deficient number, since it is larger than the sum of its proper divisors (524247524).

661358044 is a wasteful number, since it uses less digits than its factorization.

661358044 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4032716 (or 4032714 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 37.

The square root of 661358044 is about 25716.8824704706. The cubic root of 661358044 is about 871.2555281389.

The spelling of 661358044 in words is "six hundred sixty-one million, three hundred fifty-eight thousand, forty-four".