661361544 has 32 divisors (see below), whose sum is σ = 1837116000. Its totient is φ = 220453776.

The previous prime is 661361539. The next prime is 661361563. The reversal of 661361544 is 445163166.

It is a happy number.

661361544 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 661361499 and 661361508.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1530714 + ... + 1531145.

It is an arithmetic number, because the mean of its divisors is an integer number (57409875).

Almost surely, 2^661361544 is an apocalyptic number.

It is an amenable number.

661361544 is an abundant number, since it is smaller than the sum of its proper divisors (1175754456).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

661361544 is a wasteful number, since it uses less digits than its factorization.

661361544 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3061874 (or 3061864 counting only the distinct ones).

The product of its digits is 51840, while the sum is 36.

The square root of 661361544 is about 25716.9505190643. The cubic root of 661361544 is about 871.2570650719.

The spelling of 661361544 in words is "six hundred sixty-one million, three hundred sixty-one thousand, five hundred forty-four".