21349511 has 2 divisors, whose sum is σ = 21349512. Its totient is φ = 21349510.

The previous prime is 21349459. The next prime is 21349519. The reversal of 21349511 is 11594312.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21349511 - 2¹⁰ = 21348487 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21349519) 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 as a sum of consecutive naturals, namely, 10674755 + 10674756.

It is an arithmetic number, because the mean of its divisors is an integer number (10674756).

Almost surely, 2^21349511 is an apocalyptic number.

21349511 is a deficient number, since it is larger than the sum of its proper divisors (1).

21349511 is an equidigital number, since it uses as much as digits as its factorization.

21349511 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1080, while the sum is 26.

The square root of 21349511 is about 4620.5531054193. The cubic root of 21349511 is about 277.4145980739.

The spelling of 21349511 in words is "twenty-one million, three hundred forty-nine thousand, five hundred eleven".