21759500851 has 8 divisors (see below), whose sum is σ = 23844086784. Its totient is φ = 19692656520.

The previous prime is 21759500839. The next prime is 21759500899. The reversal of 21759500851 is 15800595712.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21759500851 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21759500798 and 21759500807.

It is not an unprimeable number, because it can be changed into a prime (21759500051) 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 7 ways as a sum of consecutive naturals, for example, 4432831 + ... + 4437736.

It is an arithmetic number, because the mean of its divisors is an integer number (2980510848).

Almost surely, 2^21759500851 is an apocalyptic number.

21759500851 is a deficient number, since it is larger than the sum of its proper divisors (2084585933).

21759500851 is a wasteful number, since it uses less digits than its factorization.

21759500851 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8870801.

The product of its (nonzero) digits is 126000, while the sum is 43.

The spelling of 21759500851 in words is "twenty-one billion, seven hundred fifty-nine million, five hundred thousand, eight hundred fifty-one".