21532811 has 2 divisors, whose sum is σ = 21532812. Its totient is φ = 21532810.

The previous prime is 21532801. The next prime is 21532837. The reversal of 21532811 is 11823512.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21532811 - 2⁶ = 21532747 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21532801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10766405 + 10766406.

It is an arithmetic number, because the mean of its divisors is an integer number (10766406).

Almost surely, 2^21532811 is an apocalyptic number.

21532811 is a deficient number, since it is larger than the sum of its proper divisors (1).

21532811 is an equidigital number, since it uses as much as digits as its factorization.

21532811 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 480, while the sum is 23.

The square root of 21532811 is about 4640.3460000306. The cubic root of 21532811 is about 278.2062673933.

The spelling of 21532811 in words is "twenty-one million, five hundred thirty-two thousand, eight hundred eleven".