21821428975 has 48 divisors (see below), whose sum is σ = 28398807360. Its totient is φ = 16617036800.

The previous prime is 21821428969. The next prime is 21821429017. The reversal of 21821428975 is 57982412812.

It is a happy number.

It is not a de Polignac number, because 21821428975 - 2¹³ = 21821420783 is a prime.

It is a hoax number, since the sum of its digits (49) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

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 47 ways as a sum of consecutive naturals, for example, 10701006 + ... + 10703044.

It is an arithmetic number, because the mean of its divisors is an integer number (591641820).

Almost surely, 2^21821428975 is an apocalyptic number.

21821428975 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21821428975 is a deficient number, since it is larger than the sum of its proper divisors (6577378385).

21821428975 is a wasteful number, since it uses less digits than its factorization.

21821428975 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2340 (or 2335 counting only the distinct ones).

The product of its digits is 645120, while the sum is 49.

The spelling of 21821428975 in words is "twenty-one billion, eight hundred twenty-one million, four hundred twenty-eight thousand, nine hundred seventy-five".