21766337720 has 16 divisors (see below), whose sum is σ = 48974259960. Its totient is φ = 8706535072.

The previous prime is 21766337711. The next prime is 21766337729. The reversal of 21766337720 is 2773366712.

It is an interprime number because it is at equal distance from previous prime (21766337711) and next prime (21766337729).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21766337729) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 272079182 + ... + 272079261.

Almost surely, 2^21766337720 is an apocalyptic number.

21766337720 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21766337720 is an abundant number, since it is smaller than the sum of its proper divisors (27207922240).

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

21766337720 is a wasteful number, since it uses less digits than its factorization.

21766337720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 544158454 (or 544158450 counting only the distinct ones).

The product of its (nonzero) digits is 444528, while the sum is 44.

The spelling of 21766337720 in words is "twenty-one billion, seven hundred sixty-six million, three hundred thirty-seven thousand, seven hundred twenty".