21139219 has 4 divisors (see below), whose sum is σ = 21231760. Its totient is φ = 21046680.

The previous prime is 21139213. The next prime is 21139243. The reversal of 21139219 is 91293112.

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 21139219 - 2⁷ = 21139091 is a prime.

It is a super-2 number, since 2×21139219² = 893733159859922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21139213) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 45927 + ... + 46384.

It is an arithmetic number, because the mean of its divisors is an integer number (5307940).

Almost surely, 2^21139219 is an apocalyptic number.

21139219 is a deficient number, since it is larger than the sum of its proper divisors (92541).

21139219 is an equidigital number, since it uses as much as digits as its factorization.

21139219 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 92540.

The product of its digits is 972, while the sum is 28.

The square root of 21139219 is about 4597.7406407930. The cubic root of 21139219 is about 276.5007493764.

The spelling of 21139219 in words is "twenty-one million, one hundred thirty-nine thousand, two hundred nineteen".