21666447075480 has 64 divisors (see below), whose sum is σ = 65240974562400. Its totient is φ = 5756240701440.

The previous prime is 21666447075479. The next prime is 21666447075487. The reversal of 21666447075480 is 8457074466612.

It is a Harshad number since it is a multiple of its sum of digits (60).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21666447075487) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 335569441 + ... + 335634000.

Almost surely, 2^{21666447075480} is an apocalyptic number.

21666447075480 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21666447075480 is an abundant number, since it is smaller than the sum of its proper divisors (43574527486920).

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

21666447075480 is a wasteful number, since it uses less digits than its factorization.

21666447075480 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 671203724 (or 671203720 counting only the distinct ones).

The product of its (nonzero) digits is 54190080, while the sum is 60.

The spelling of 21666447075480 in words is "twenty-one trillion, six hundred sixty-six billion, four hundred forty-seven million, seventy-five thousand, four hundred eighty".