21801719 has 2 divisors, whose sum is σ = 21801720. Its totient is φ = 21801718.

The previous prime is 21801673. The next prime is 21801727. The reversal of 21801719 is 91710812.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21801719 - 2¹² = 21797623 is a prime.

It is a super-2 number, since 2×21801719² = 950629902709922, which contains 22 as substring.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 21801691 and 21801700.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21801019) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10900859 + 10900860.

It is an arithmetic number, because the mean of its divisors is an integer number (10900860).

Almost surely, 2^21801719 is an apocalyptic number.

21801719 is a deficient number, since it is larger than the sum of its proper divisors (1).

21801719 is an equidigital number, since it uses as much as digits as its factorization.

21801719 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1008, while the sum is 29.

The square root of 21801719 is about 4669.2310930174. The cubic root of 21801719 is about 279.3595865389.

The spelling of 21801719 in words is "twenty-one million, eight hundred one thousand, seven hundred nineteen".