21361719 has 16 divisors (see below), whose sum is σ = 31017600. Its totient is φ = 13025376.

The previous prime is 21361709. The next prime is 21361721. The reversal of 21361719 is 91716312.

It is not a de Polignac number, because 21361719 - 2⁷ = 21361591 is a prime.

It is a super-2 number, since 2×21361719² = 912646077269922, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21361709) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4809 + ... + 8114.

It is an arithmetic number, because the mean of its divisors is an integer number (1938600).

Almost surely, 2^21361719 is an apocalyptic number.

21361719 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

21361719 is a deficient number, since it is larger than the sum of its proper divisors (9655881).

21361719 is a wasteful number, since it uses less digits than its factorization.

21361719 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12974.

The product of its digits is 2268, while the sum is 30.

The square root of 21361719 is about 4621.8739705881. The cubic root of 21361719 is about 277.4674647352.

The spelling of 21361719 in words is "twenty-one million, three hundred sixty-one thousand, seven hundred nineteen".