21600921751 has 2 divisors, whose sum is σ = 21600921752. Its totient is φ = 21600921750.

The previous prime is 21600921697. The next prime is 21600921767. The reversal of 21600921751 is 15712900612.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21600921751 - 2¹⁹ = 21600397463 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21600921781) 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 as a sum of consecutive naturals, namely, 10800460875 + 10800460876.

It is an arithmetic number, because the mean of its divisors is an integer number (10800460876).

Almost surely, 2^21600921751 is an apocalyptic number.

21600921751 is a deficient number, since it is larger than the sum of its proper divisors (1).

21600921751 is an equidigital number, since it uses as much as digits as its factorization.

21600921751 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7560, while the sum is 34.

The spelling of 21600921751 in words is "twenty-one billion, six hundred million, nine hundred twenty-one thousand, seven hundred fifty-one".