21551772511 has 8 divisors (see below), whose sum is σ = 21629721600. Its totient is φ = 21473962488.

The previous prime is 21551772499. The next prime is 21551772521. The reversal of 21551772511 is 11527715512.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21551772511 - 2⁷ = 21551772383 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21551772521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 280890 + ... + 349288.

It is an arithmetic number, because the mean of its divisors is an integer number (2703715200).

Almost surely, 2^21551772511 is an apocalyptic number.

21551772511 is a deficient number, since it is larger than the sum of its proper divisors (77949089).

21551772511 is an equidigital number, since it uses as much as digits as its factorization.

21551772511 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69533.

The product of its digits is 24500, while the sum is 37.

The spelling of 21551772511 in words is "twenty-one billion, five hundred fifty-one million, seven hundred seventy-two thousand, five hundred eleven".