21623267 has 2 divisors, whose sum is σ = 21623268. Its totient is φ = 21623266.

The previous prime is 21623249. The next prime is 21623279. The reversal of 21623267 is 76232612.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21623267 is a prime.

It is not a weakly prime, because it can be changed into another prime (21623867) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10811633 + 10811634.

It is an arithmetic number, because the mean of its divisors is an integer number (10811634).

Almost surely, 2^21623267 is an apocalyptic number.

21623267 is a deficient number, since it is larger than the sum of its proper divisors (1).

21623267 is an equidigital number, since it uses as much as digits as its factorization.

21623267 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6048, while the sum is 29.

The square root of 21623267 is about 4650.0824723869. The cubic root of 21623267 is about 278.5952902887.

Adding to 21623267 its reverse (76232612), we get a palindrome (97855879).

The spelling of 21623267 in words is "twenty-one million, six hundred twenty-three thousand, two hundred sixty-seven".