21776233 has 2 divisors, whose sum is σ = 21776234. Its totient is φ = 21776232.

The previous prime is 21776221. The next prime is 21776243. The reversal of 21776233 is 33267712.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14953689 + 6822544 = 3867^2 + 2612^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21776233 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21776195 and 21776204.

It is not a weakly prime, because it can be changed into another prime (21776213) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10888116 + 10888117.

It is an arithmetic number, because the mean of its divisors is an integer number (10888117).

Almost surely, 2^21776233 is an apocalyptic number.

It is an amenable number.

21776233 is a deficient number, since it is larger than the sum of its proper divisors (1).

21776233 is an equidigital number, since it uses as much as digits as its factorization.

21776233 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10584, while the sum is 31.

The square root of 21776233 is about 4666.5011518267. The cubic root of 21776233 is about 279.2506878700.

The spelling of 21776233 in words is "twenty-one million, seven hundred seventy-six thousand, two hundred thirty-three".