21776801 has 2 divisors, whose sum is σ = 21776802. Its totient is φ = 21776800.

The previous prime is 21776789. The next prime is 21776803. The reversal of 21776801 is 10867712.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16394401 + 5382400 = 4049^2 + 2320^2 .

It is a cyclic number.

It is not a de Polignac number, because 21776801 - 2¹⁰ = 21775777 is a prime.

Together with 21776803, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21776803) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10888400 + 10888401.

It is an arithmetic number, because the mean of its divisors is an integer number (10888401).

Almost surely, 2^21776801 is an apocalyptic number.

It is an amenable number.

21776801 is a deficient number, since it is larger than the sum of its proper divisors (1).

21776801 is an equidigital number, since it uses as much as digits as its factorization.

21776801 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4704, while the sum is 32.

The square root of 21776801 is about 4666.5620107312. The cubic root of 21776801 is about 279.2531157924.

The spelling of 21776801 in words is "twenty-one million, seven hundred seventy-six thousand, eight hundred one".