661913226 has 96 divisors (see below), whose sum is σ = 1614936960. Its totient is φ = 194527872.

The previous prime is 661913201. The next prime is 661913227. The reversal of 661913226 is 622319166.

It is a happy number.

661913226 is a `hidden beast` number, since 6 + 619 + 1 + 32 + 2 + 6 = 666.

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (661913227) by changing a digit.

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 47 ways as a sum of consecutive naturals, for example, 698485 + ... + 699431.

It is an arithmetic number, because the mean of its divisors is an integer number (16822260).

Almost surely, 2^661913226 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 661913226, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (807468480).

661913226 is an abundant number, since it is smaller than the sum of its proper divisors (953023734).

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

661913226 is a wasteful number, since it uses less digits than its factorization.

661913226 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1100 (or 1097 counting only the distinct ones).

The product of its digits is 23328, while the sum is 36.

The square root of 661913226 is about 25727.6743216327. The cubic root of 661913226 is about 871.4992539614.

The spelling of 661913226 in words is "six hundred sixty-one million, nine hundred thirteen thousand, two hundred twenty-six".