21840319 has 2 divisors, whose sum is σ = 21840320. Its totient is φ = 21840318.

The previous prime is 21840283. The next prime is 21840361. The reversal of 21840319 is 91304812.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21840319 - 2¹³ = 21832127 is a prime.

It is a super-2 number, since 2×21840319² = 953999068043522, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21840389) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10920159 + 10920160.

It is an arithmetic number, because the mean of its divisors is an integer number (10920160).

Almost surely, 2^21840319 is an apocalyptic number.

21840319 is a deficient number, since it is larger than the sum of its proper divisors (1).

21840319 is an equidigital number, since it uses as much as digits as its factorization.

21840319 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1728, while the sum is 28.

The square root of 21840319 is about 4673.3627079438. The cubic root of 21840319 is about 279.5243582916.

It can be divided in two parts, 2 and 1840319, that added together give a triangular number (1840321 = T₁₉₁₈).

The spelling of 21840319 in words is "twenty-one million, eight hundred forty thousand, three hundred nineteen".