21124619 has 2 divisors, whose sum is σ = 21124620. Its totient is φ = 21124618.

The previous prime is 21124601. The next prime is 21124627. The reversal of 21124619 is 91642112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21124619 - 2¹² = 21120523 is a prime.

It is a super-2 number, since 2×21124619² = 892499055790322, which contains 22 as substring.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (21124699) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10562309 + 10562310.

It is an arithmetic number, because the mean of its divisors is an integer number (10562310).

Almost surely, 2^21124619 is an apocalyptic number.

21124619 is a deficient number, since it is larger than the sum of its proper divisors (1).

21124619 is an equidigital number, since it uses as much as digits as its factorization.

21124619 is an evil number, because the sum of its binary digits is even.

The product of its digits is 864, while the sum is 26.

The square root of 21124619 is about 4596.1526301897. The cubic root of 21124619 is about 276.4370787700.

The spelling of 21124619 in words is "twenty-one million, one hundred twenty-four thousand, six hundred nineteen".