21179519 has 2 divisors, whose sum is σ = 21179520. Its totient is φ = 21179518.

The previous prime is 21179507. The next prime is 21179531. The reversal of 21179519 is 91597112.

It is a balanced prime because it is at equal distance from previous prime (21179507) and next prime (21179531).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21179519 is a prime.

It is a super-2 number, since 2×21179519² = 897144050142722, which contains 22 as substring.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21179539) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10589759 + 10589760.

It is an arithmetic number, because the mean of its divisors is an integer number (10589760).

Almost surely, 2^21179519 is an apocalyptic number.

21179519 is a deficient number, since it is larger than the sum of its proper divisors (1).

21179519 is an equidigital number, since it uses as much as digits as its factorization.

21179519 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5670, while the sum is 35.

The square root of 21179519 is about 4602.1211413869. The cubic root of 21179519 is about 276.6763456881.

The spelling of 21179519 in words is "twenty-one million, one hundred seventy-nine thousand, five hundred nineteen".