21740219 has 2 divisors, whose sum is σ = 21740220. Its totient is φ = 21740218.

The previous prime is 21740197. The next prime is 21740231. The reversal of 21740219 is 91204712.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21740219 - 2¹⁶ = 21674683 is a prime.

It is a super-2 number, since 2×21740219² = 945274244335922, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21740239) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10870109 + 10870110.

It is an arithmetic number, because the mean of its divisors is an integer number (10870110).

Almost surely, 2^21740219 is an apocalyptic number.

21740219 is a deficient number, since it is larger than the sum of its proper divisors (1).

21740219 is an equidigital number, since it uses as much as digits as its factorization.

21740219 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1008, while the sum is 26.

The square root of 21740219 is about 4662.6407753547. The cubic root of 21740219 is about 279.0966593397.

The spelling of 21740219 in words is "twenty-one million, seven hundred forty thousand, two hundred nineteen".