21798311945 has 8 divisors (see below), whose sum is σ = 26795973960. Its totient is φ = 17013316480.

The previous prime is 21798311929. The next prime is 21798311957. The reversal of 21798311945 is 54911389712.

It can be written as a sum of positive squares in 4 ways, for example, as 1628176 + 21796683769 = 1276^2 + 147637^2 .

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

It is not a de Polignac number, because 21798311945 - 2⁴ = 21798311929 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21798311893 and 21798311902.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 53166410 + ... + 53166819.

It is an arithmetic number, because the mean of its divisors is an integer number (3349496745).

Almost surely, 2^21798311945 is an apocalyptic number.

It is an amenable number.

21798311945 is a deficient number, since it is larger than the sum of its proper divisors (4997662015).

21798311945 is a wasteful number, since it uses less digits than its factorization.

21798311945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 106333275.

The product of its digits is 544320, while the sum is 50.

The spelling of 21798311945 in words is "twenty-one billion, seven hundred ninety-eight million, three hundred eleven thousand, nine hundred forty-five".