661332224 has 54 divisors (see below), whose sum is σ = 1535633694. Its totient is φ = 283422720.

The previous prime is 661332223. The next prime is 661332233. The reversal of 661332224 is 422233166.

It can be written as a sum of positive squares in only one way, i.e., 429318400 + 232013824 = 20720^2 + 15232^2 .

It is not an unprimeable number, because it can be changed into a prime (661332223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 13817 + ... + 38904.

It is an arithmetic number, because the mean of its divisors is an integer number (28437661).

Almost surely, 2^661332224 is an apocalyptic number.

661332224 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

661332224 is an abundant number, since it is smaller than the sum of its proper divisors (874301470).

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

661332224 is an equidigital number, since it uses as much as digits as its factorization.

661332224 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52751 (or 52730 counting only the distinct ones).

The product of its digits is 10368, while the sum is 29.

The square root of 661332224 is about 25716.3804607103. The cubic root of 661332224 is about 871.2441897972.

The spelling of 661332224 in words is "six hundred sixty-one million, three hundred thirty-two thousand, two hundred twenty-four".