21806450547759 has 12 divisors (see below), whose sum is σ = 31498301927352. Its totient is φ = 14537589584400.

The previous prime is 21806450547709. The next prime is 21806450547793. The reversal of 21806450547759 is 95774505460812.

It is a happy number.

21806450547759 is a `hidden beast` number, since 2 + 1 + 8 + 0 + 6 + 4 + 505 + 4 + 77 + 59 = 666.

It is not a de Polignac number, because 21806450547759 - 2⁸ = 21806450547503 is a prime.

It is a super-2 number, since 2×21806450547759² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21806450547696 and 21806450547705.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21806450547709) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 390972 + ... + 6615569.

It is an arithmetic number, because the mean of its divisors is an integer number (2624858493946).

Almost surely, 2^{21806450547759} is an apocalyptic number.

21806450547759 is a deficient number, since it is larger than the sum of its proper divisors (9691851379593).

21806450547759 is a wasteful number, since it uses less digits than its factorization.

21806450547759 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7352358 (or 7352355 counting only the distinct ones).

The product of its (nonzero) digits is 84672000, while the sum is 63.

The spelling of 21806450547759 in words is "twenty-one trillion, eight hundred six billion, four hundred fifty million, five hundred forty-seven thousand, seven hundred fifty-nine".