661625523644022 has 96 divisors (see below), whose sum is σ = 1644146482038528. Its totient is φ = 188362556198208.

The previous prime is 661625523643991. The next prime is 661625523644051. The reversal of 661625523644022 is 220446325526166.

661625523644022 is a `hidden beast` number, since 6 + 6 + 1 + 6 + 2 + 552 + 3 + 64 + 4 + 0 + 22 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 661625523644022.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1356650073 + ... + 1357137675.

It is an arithmetic number, because the mean of its divisors is an integer number (17126525854568).

Almost surely, 2^{661625523644022} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 661625523644022, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (822073241019264).

661625523644022 is an abundant number, since it is smaller than the sum of its proper divisors (982520958394506).

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

661625523644022 is a wasteful number, since it uses less digits than its factorization.

661625523644022 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 525954 (or 525951 counting only the distinct ones).

The product of its (nonzero) digits is 24883200, while the sum is 54.

The spelling of 661625523644022 in words is "six hundred sixty-one trillion, six hundred twenty-five billion, five hundred twenty-three million, six hundred forty-four thousand, twenty-two".