21720203219 has 8 divisors (see below), whose sum is σ = 25517441712. Its totient is φ = 18226743840.

The previous prime is 21720203213. The next prime is 21720203231. The reversal of 21720203219 is 91230202712.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21720203219 is a prime.

It is a super-2 number, since 2×21720203219² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21720203191 and 21720203200.

It is not an unprimeable number, because it can be changed into a prime (21720203213) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 75944624 + ... + 75944909.

It is an arithmetic number, because the mean of its divisors is an integer number (3189680214).

Almost surely, 2^21720203219 is an apocalyptic number.

21720203219 is a deficient number, since it is larger than the sum of its proper divisors (3797238493).

21720203219 is a wasteful number, since it uses less digits than its factorization.

21720203219 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 151889557.

The product of its (nonzero) digits is 3024, while the sum is 29.

The spelling of 21720203219 in words is "twenty-one billion, seven hundred twenty million, two hundred three thousand, two hundred nineteen".