20621233104561 has 32 divisors (see below), whose sum is σ = 32347356940800. Its totient is φ = 12938683080960.

The previous prime is 20621233104547. The next prime is 20621233104587. The reversal of 20621233104561 is 16540133212602.

20621233104561 is a `hidden beast` number, since 2 + 0 + 62 + 1 + 2 + 3 + 31 + 0 + 4 + 561 = 666.

It is not a de Polignac number, because 20621233104561 - 2³⁹ = 20071477290673 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20621233104361) 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 31 ways as a sum of consecutive naturals, for example, 68087976 + ... + 68390166.

It is an arithmetic number, because the mean of its divisors is an integer number (1010854904400).

Almost surely, 2^{20621233104561} is an apocalyptic number.

It is an amenable number.

20621233104561 is a deficient number, since it is larger than the sum of its proper divisors (11726123836239).

20621233104561 is a wasteful number, since it uses less digits than its factorization.

20621233104561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 450886 (or 450880 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 36.

The spelling of 20621233104561 in words is "twenty trillion, six hundred twenty-one billion, two hundred thirty-three million, one hundred four thousand, five hundred sixty-one".