21421319 has 2 divisors, whose sum is σ = 21421320. Its totient is φ = 21421318.

The previous prime is 21421273. The next prime is 21421333. The reversal of 21421319 is 91312412.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21421319 - 2¹⁶ = 21355783 is a prime.

It is a super-2 number, since 2×21421319² = 917745815399522, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21421294 and 21421303.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21421399) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10710659 + 10710660.

It is an arithmetic number, because the mean of its divisors is an integer number (10710660).

Almost surely, 2^21421319 is an apocalyptic number.

21421319 is a deficient number, since it is larger than the sum of its proper divisors (1).

21421319 is an equidigital number, since it uses as much as digits as its factorization.

21421319 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 432, while the sum is 23.

The square root of 21421319 is about 4628.3170807541. The cubic root of 21421319 is about 277.7252733416.

The spelling of 21421319 in words is "twenty-one million, four hundred twenty-one thousand, three hundred nineteen".