661722512 has 40 divisors (see below), whose sum is σ = 1459460160. Its totient is φ = 287703680.

The previous prime is 661722511. The next prime is 661722547. The reversal of 661722512 is 215227166.

It is not an unprimeable number, because it can be changed into a prime (661722511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 77687 + ... + 85782.

It is an arithmetic number, because the mean of its divisors is an integer number (36486504).

Almost surely, 2^661722512 is an apocalyptic number.

It is an amenable number.

661722512 is an abundant number, since it is smaller than the sum of its proper divisors (797737648).

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

661722512 is a wasteful number, since it uses less digits than its factorization.

661722512 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 163511 (or 163505 counting only the distinct ones).

The product of its digits is 10080, while the sum is 32.

The square root of 661722512 is about 25723.9676566427. The cubic root of 661722512 is about 871.4155455700.

Adding to 661722512 its reverse (215227166), we get a palindrome (876949678).

The spelling of 661722512 in words is "six hundred sixty-one million, seven hundred twenty-two thousand, five hundred twelve".