21872341 has 2 divisors, whose sum is σ = 21872342. Its totient is φ = 21872340.

The previous prime is 21872317. The next prime is 21872369. The reversal of 21872341 is 14327812.

It is an a-pointer prime, because the next prime (21872369) can be obtained adding 21872341 to its sum of digits (28).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13727025 + 8145316 = 3705^2 + 2854^2 .

It is a cyclic number.

It is not a de Polignac number, because 21872341 - 2⁵ = 21872309 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21872371) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10936170 + 10936171.

It is an arithmetic number, because the mean of its divisors is an integer number (10936171).

Almost surely, 2^21872341 is an apocalyptic number.

It is an amenable number.

21872341 is a deficient number, since it is larger than the sum of its proper divisors (1).

21872341 is an equidigital number, since it uses as much as digits as its factorization.

21872341 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2688, while the sum is 28.

The square root of 21872341 is about 4676.7874657718. The cubic root of 21872341 is about 279.6609032749.

The spelling of 21872341 in words is "twenty-one million, eight hundred seventy-two thousand, three hundred forty-one".