21510719 has 2 divisors, whose sum is σ = 21510720. Its totient is φ = 21510718.

The previous prime is 21510703. The next prime is 21510733. The reversal of 21510719 is 91701512.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21510719 - 2⁴ = 21510703 is a prime.

It is a super-2 number, since 2×21510719² = 925422063793922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21510919) 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, 10755359 + 10755360.

It is an arithmetic number, because the mean of its divisors is an integer number (10755360).

Almost surely, 2^21510719 is an apocalyptic number.

21510719 is a deficient number, since it is larger than the sum of its proper divisors (1).

21510719 is an equidigital number, since it uses as much as digits as its factorization.

21510719 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 630, while the sum is 26.

The square root of 21510719 is about 4637.9649632139. The cubic root of 21510719 is about 278.1110911531. Note that the first 3 decimals are identical.

The spelling of 21510719 in words is "twenty-one million, five hundred ten thousand, seven hundred nineteen".