21720510003 has 64 divisors (see below), whose sum is σ = 33439150080. Its totient is φ = 12449894400.

The previous prime is 21720510001. The next prime is 21720510011. The reversal of 21720510003 is 30001502712.

It is not a de Polignac number, because 21720510003 - 2¹ = 21720510001 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21720510001) by changing a digit.

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 63 ways as a sum of consecutive naturals, for example, 9521223 + ... + 9523503.

It is an arithmetic number, because the mean of its divisors is an integer number (522486720).

Almost surely, 2^21720510003 is an apocalyptic number.

21720510003 is a deficient number, since it is larger than the sum of its proper divisors (11718640077).

21720510003 is a wasteful number, since it uses less digits than its factorization.

21720510003 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2668.

The product of its (nonzero) digits is 420, while the sum is 21.

The spelling of 21720510003 in words is "twenty-one billion, seven hundred twenty million, five hundred ten thousand, three".