21839801 has 2 divisors, whose sum is σ = 21839802. Its totient is φ = 21839800.

The previous prime is 21839791. The next prime is 21839827. The reversal of 21839801 is 10893812.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17935225 + 3904576 = 4235^2 + 1976^2 .

It is a cyclic number.

It is not a de Polignac number, because 21839801 - 2⁶ = 21839737 is a prime.

It is a Chen prime.

It is equal to p_1379741 and since 21839801 and 1379741 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (21839401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10919900 + 10919901.

It is an arithmetic number, because the mean of its divisors is an integer number (10919901).

Almost surely, 2^21839801 is an apocalyptic number.

It is an amenable number.

21839801 is a deficient number, since it is larger than the sum of its proper divisors (1).

21839801 is an equidigital number, since it uses as much as digits as its factorization.

21839801 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3456, while the sum is 32.

The square root of 21839801 is about 4673.3072871362. The cubic root of 21839801 is about 279.5221483916.

The spelling of 21839801 in words is "twenty-one million, eight hundred thirty-nine thousand, eight hundred one".