21358811 has 2 divisors, whose sum is σ = 21358812. Its totient is φ = 21358810.

The previous prime is 21358787. The next prime is 21358837. The reversal of 21358811 is 11885312.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21358811 - 2⁶ = 21358747 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21358861) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10679405 + 10679406.

It is an arithmetic number, because the mean of its divisors is an integer number (10679406).

Almost surely, 2^21358811 is an apocalyptic number.

21358811 is a deficient number, since it is larger than the sum of its proper divisors (1).

21358811 is an equidigital number, since it uses as much as digits as its factorization.

21358811 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1920, while the sum is 29.

The square root of 21358811 is about 4621.5593688711. The cubic root of 21358811 is about 277.4548734888.

The spelling of 21358811 in words is "twenty-one million, three hundred fifty-eight thousand, eight hundred eleven".