21130719 has 4 divisors (see below), whose sum is σ = 28174296. Its totient is φ = 14087144.

The previous prime is 21130699. The next prime is 21130727. The reversal of 21130719 is 91703112.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21130719 - 2⁷ = 21130591 is a prime.

It is a super-2 number, since 2×21130719² = 893014570913922, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21130619) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3521784 + ... + 3521789.

It is an arithmetic number, because the mean of its divisors is an integer number (7043574).

Almost surely, 2^21130719 is an apocalyptic number.

21130719 is a deficient number, since it is larger than the sum of its proper divisors (7043577).

21130719 is an equidigital number, since it uses as much as digits as its factorization.

21130719 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7043576.

The product of its (nonzero) digits is 378, while the sum is 24.

The square root of 21130719 is about 4596.8161807930. The cubic root of 21130719 is about 276.4636844396.

The spelling of 21130719 in words is "twenty-one million, one hundred thirty thousand, seven hundred nineteen".