21974687280 has 720 divisors, whose sum is σ = 94122100800. Its totient is φ = 4473999360.

The previous prime is 21974687197. The next prime is 21974687299. The reversal of 21974687280 is 8278647912.

It is a happy number.

21974687280 is a `hidden beast` number, since 21 + 97 + 468 + 72 + 8 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (720).

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

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 in 143 ways as a sum of consecutive naturals, for example, 62964546 + ... + 62964894.

It is an arithmetic number, because the mean of its divisors is an integer number (130725140).

Almost surely, 2^21974687280 is an apocalyptic number.

21974687280 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21974687280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (47061050400).

21974687280 is an abundant number, since it is smaller than the sum of its proper divisors (72147413520).

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

21974687280 is a wasteful number, since it uses less digits than its factorization.

21974687280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 450 (or 410 counting only the distinct ones).

The product of its (nonzero) digits is 2709504, while the sum is 54.

The spelling of 21974687280 in words is "twenty-one billion, nine hundred seventy-four million, six hundred eighty-seven thousand, two hundred eighty".