21125219 has 2 divisors, whose sum is σ = 21125220. Its totient is φ = 21125218.

The previous prime is 21125183. The next prime is 21125227. The reversal of 21125219 is 91252112.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21125219 is a prime.

It is a super-2 number, since 2×21125219² = 892549755595922, which contains 22 as substring.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 21125194 and 21125203.

It is not a weakly prime, because it can be changed into another prime (21125239) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10562609 + 10562610.

It is an arithmetic number, because the mean of its divisors is an integer number (10562610).

Almost surely, 2^21125219 is an apocalyptic number.

21125219 is a deficient number, since it is larger than the sum of its proper divisors (1).

21125219 is an equidigital number, since it uses as much as digits as its factorization.

21125219 is an evil number, because the sum of its binary digits is even.

The product of its digits is 360, while the sum is 23.

The square root of 21125219 is about 4596.2179017101. The cubic root of 21125219 is about 276.4396959482.

The spelling of 21125219 in words is "twenty-one million, one hundred twenty-five thousand, two hundred nineteen".