194097780621 has 24 divisors (see below), whose sum is σ = 280781787000. Its totient is φ = 129205573632.

The previous prime is 194097780589. The next prime is 194097780637. The reversal of 194097780621 is 126087790491.

194097780621 is a `hidden beast` number, since 1 + 9 + 4 + 0 + 9 + 7 + 7 + 8 + 0 + 621 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 1890945225 + 192206835396 = 43485^2 + 438414^2 .

It is not a de Polignac number, because 194097780621 - 2⁵ = 194097780589 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (194097780641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 39536715 + ... + 39541623.

It is an arithmetic number, because the mean of its divisors is an integer number (11699241125).

Almost surely, 2^194097780621 is an apocalyptic number.

It is an amenable number.

194097780621 is a deficient number, since it is larger than the sum of its proper divisors (86684006379).

194097780621 is a wasteful number, since it uses less digits than its factorization.

194097780621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10573 (or 10570 counting only the distinct ones).

The product of its (nonzero) digits is 1524096, while the sum is 54.

The spelling of 194097780621 in words is "one hundred ninety-four billion, ninety-seven million, seven hundred eighty thousand, six hundred twenty-one".