21115719 has 6 divisors (see below), whose sum is σ = 30500496. Its totient is φ = 14077140.

The previous prime is 21115657. The next prime is 21115723. The reversal of 21115719 is 91751112.

It is not a de Polignac number, because 21115719 - 2¹¹ = 21113671 is a prime.

It is a super-2 number, since 2×21115719² = 891747177773922, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21115692 and 21115701.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21115729) 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 in 5 ways as a sum of consecutive naturals, for example, 1173087 + ... + 1173104.

It is an arithmetic number, because the mean of its divisors is an integer number (5083416).

Almost surely, 2^21115719 is an apocalyptic number.

21115719 is a deficient number, since it is larger than the sum of its proper divisors (9384777).

21115719 is a wasteful number, since it uses less digits than its factorization.

21115719 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2346197 (or 2346194 counting only the distinct ones).

The product of its digits is 630, while the sum is 27.

The square root of 21115719 is about 4595.1843270972. The cubic root of 21115719 is about 276.3982514726.

The spelling of 21115719 in words is "twenty-one million, one hundred fifteen thousand, seven hundred nineteen".