20551610772521 has 4 divisors (see below), whose sum is σ = 20551798967952. Its totient is φ = 20551422577092.

The previous prime is 20551610772491. The next prime is 20551610772533. The reversal of 20551610772521 is 12527701615502.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20551610772521 - 2¹⁸ = 20551610510377 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20551610742521) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 93933815 + ... + 94152348.

It is an arithmetic number, because the mean of its divisors is an integer number (5137949741988).

Almost surely, 2^{20551610772521} is an apocalyptic number.

It is an amenable number.

20551610772521 is a deficient number, since it is larger than the sum of its proper divisors (188195431).

20551610772521 is a wasteful number, since it uses less digits than its factorization.

20551610772521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 188195430.

The product of its (nonzero) digits is 294000, while the sum is 44.

The spelling of 20551610772521 in words is "twenty trillion, five hundred fifty-one billion, six hundred ten million, seven hundred seventy-two thousand, five hundred twenty-one".