21220009975 has 12 divisors (see below), whose sum is σ = 26323040416. Its totient is φ = 16969409280.

The previous prime is 21220009973. The next prime is 21220010023. The reversal of 21220009975 is 57990002212.

It is not a de Polignac number, because 21220009975 - 2¹ = 21220009973 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21220009973) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 98847 + ... + 228496.

Almost surely, 2^21220009975 is an apocalyptic number.

21220009975 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21220009975 is a deficient number, since it is larger than the sum of its proper divisors (5103030441).

21220009975 is a wasteful number, since it uses less digits than its factorization.

21220009975 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 329946 (or 329941 counting only the distinct ones).

The product of its (nonzero) digits is 22680, while the sum is 37.

The spelling of 21220009975 in words is "twenty-one billion, two hundred twenty million, nine thousand, nine hundred seventy-five".