21197219 has 4 divisors (see below), whose sum is σ = 21435480. Its totient is φ = 20958960.

The previous prime is 21197207. The next prime is 21197221. The reversal of 21197219 is 91279112.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21197219 - 2⁴ = 21197203 is a prime.

It is a super-2 number, since 2×21197219² = 898644186667922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21197269) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 118997 + ... + 119174.

It is an arithmetic number, because the mean of its divisors is an integer number (5358870).

Almost surely, 2^21197219 is an apocalyptic number.

21197219 is a deficient number, since it is larger than the sum of its proper divisors (238261).

21197219 is an equidigital number, since it uses as much as digits as its factorization.

21197219 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 238260.

The product of its digits is 2268, while the sum is 32.

The square root of 21197219 is about 4604.0437660822. The cubic root of 21197219 is about 276.7533982365.

The spelling of 21197219 in words is "twenty-one million, one hundred ninety-seven thousand, two hundred nineteen".