21767411 has 2 divisors, whose sum is σ = 21767412. Its totient is φ = 21767410.

The previous prime is 21767381. The next prime is 21767413. The reversal of 21767411 is 11476712.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21767411 - 2¹⁴ = 21751027 is a prime.

It is a Sophie Germain prime.

Together with 21767413, 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 (21767413) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10883705 + 10883706.

It is an arithmetic number, because the mean of its divisors is an integer number (10883706).

Almost surely, 2^21767411 is an apocalyptic number.

21767411 is the 2087-th centered decagonal number.

21767411 is a deficient number, since it is larger than the sum of its proper divisors (1).

21767411 is an equidigital number, since it uses as much as digits as its factorization.

21767411 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2352, while the sum is 29.

The square root of 21767411 is about 4665.5558082612. Note that the first 3 decimals coincide. The cubic root of 21767411 is about 279.2129727103.

The spelling of 21767411 in words is "twenty-one million, seven hundred sixty-seven thousand, four hundred eleven".