661220450 has 24 divisors (see below), whose sum is σ = 1341677520. Its totient is φ = 240443600.

The previous prime is 661220447. The next prime is 661220477. The reversal of 661220450 is 54022166.

661220450 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a hoax number, since the sum of its digits (26) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 600560 + ... + 601659.

It is an arithmetic number, because the mean of its divisors is an integer number (55903230).

Almost surely, 2^661220450 is an apocalyptic number.

661220450 is an abundant number, since it is smaller than the sum of its proper divisors (680457070).

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

661220450 is a wasteful number, since it uses less digits than its factorization.

661220450 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1202242 (or 1202237 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 26.

The square root of 661220450 is about 25714.2071625784. The cubic root of 661220450 is about 871.1951030541.

The spelling of 661220450 in words is "six hundred sixty-one million, two hundred twenty thousand, four hundred fifty".