21868783987440 has 160 divisors (see below), whose sum is σ = 73445270201856. Its totient is φ = 5350851118080.

The previous prime is 21868783987439. The next prime is 21868783987441. The reversal of 21868783987440 is 4478938786812.

It is an interprime number because it is at equal distance from previous prime (21868783987439) and next prime (21868783987441).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21868783987441) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 20464666 + ... + 21506745.

Almost surely, 2^{21868783987440} is an apocalyptic number.

21868783987440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21868783987440 is an abundant number, since it is smaller than the sum of its proper divisors (51576486214416).

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

21868783987440 is a wasteful number, since it uses less digits than its factorization.

21868783987440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41971607 (or 41971601 counting only the distinct ones).

The product of its (nonzero) digits is 1040449536, while the sum is 75.

The spelling of 21868783987440 in words is "twenty-one trillion, eight hundred sixty-eight billion, seven hundred eighty-three million, nine hundred eighty-seven thousand, four hundred forty".