21868853536720 has 40 divisors (see below), whose sum is σ = 50855693560776. Its totient is φ = 8745716195328.

The previous prime is 21868853536709. The next prime is 21868853536727. The reversal of 21868853536720 is 2763535886812.

It can be written as a sum of positive squares in 4 ways, for example, as 13109787113536 + 8759066423184 = 3620744^2 + 2959572^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21868853536727) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28133217 + ... + 28900096.

Almost surely, 2^{21868853536720} is an apocalyptic number.

21868853536720 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21868853536720 is an abundant number, since it is smaller than the sum of its proper divisors (28986840024056).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21868853536720 is a wasteful number, since it uses less digits than its factorization.

21868853536720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57038119 (or 57038113 counting only the distinct ones).

The product of its (nonzero) digits is 116121600, while the sum is 64.

The spelling of 21868853536720 in words is "twenty-one trillion, eight hundred sixty-eight billion, eight hundred fifty-three million, five hundred thirty-six thousand, seven hundred twenty".