21243032217 has 80 divisors (see below), whose sum is σ = 35580504960. Its totient is φ = 12518841600.

The previous prime is 21243032207. The next prime is 21243032233. The reversal of 21243032217 is 71223034212.

21243032217 is a `hidden beast` number, since 2 + 1 + 2 + 430 + 3 + 221 + 7 = 666.

It is not a de Polignac number, because 21243032217 - 2⁸ = 21243031961 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (21243032207) 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 79 ways as a sum of consecutive naturals, for example, 13625284 + ... + 13626842.

It is an arithmetic number, because the mean of its divisors is an integer number (444756312).

Almost surely, 2^21243032217 is an apocalyptic number.

21243032217 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

It is an amenable number.

21243032217 is a deficient number, since it is larger than the sum of its proper divisors (14337472743).

21243032217 is a wasteful number, since it uses less digits than its factorization.

21243032217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1996 (or 1987 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 27.

Adding to 21243032217 its reverse (71223034212), we get a palindrome (92466066429).

The spelling of 21243032217 in words is "twenty-one billion, two hundred forty-three million, thirty-two thousand, two hundred seventeen".