21900293648 has 10 divisors (see below), whose sum is σ = 42431818974. Its totient is φ = 10950146816.

The previous prime is 21900293641. The next prime is 21900293677. The reversal of 21900293648 is 84639200912.

It can be written as a sum of positive squares in only one way, i.e., 18902950144 + 2997343504 = 137488^2 + 54748^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21900293599 and 21900293608.

It is not an unprimeable number, because it can be changed into a prime (21900293641) 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, 684384161 + ... + 684384192.

Almost surely, 2^21900293648 is an apocalyptic number.

It is an amenable number.

21900293648 is a deficient number, since it is larger than the sum of its proper divisors (20531525326).

21900293648 is a wasteful number, since it uses less digits than its factorization.

21900293648 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1368768361 (or 1368768355 counting only the distinct ones).

The product of its (nonzero) digits is 186624, while the sum is 44.

The spelling of 21900293648 in words is "twenty-one billion, nine hundred million, two hundred ninety-three thousand, six hundred forty-eight".