21220759815 has 32 divisors (see below), whose sum is σ = 34406297856. Its totient is φ = 11167061760.

The previous prime is 21220759801. The next prime is 21220759817. The reversal of 21220759815 is 51895702212.

It is not a de Polignac number, because 21220759815 - 2⁴ = 21220759799 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21220759817) 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 31 ways as a sum of consecutive naturals, for example, 999187 + ... + 1020203.

It is an arithmetic number, because the mean of its divisors is an integer number (1075196808).

Almost surely, 2^21220759815 is an apocalyptic number.

21220759815 is a deficient number, since it is larger than the sum of its proper divisors (13185538041).

21220759815 is a wasteful number, since it uses less digits than its factorization.

21220759815 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21919.

The product of its (nonzero) digits is 100800, while the sum is 42.

The spelling of 21220759815 in words is "twenty-one billion, two hundred twenty million, seven hundred fifty-nine thousand, eight hundred fifteen".