21552667 has 2 divisors, whose sum is σ = 21552668. Its totient is φ = 21552666.

The previous prime is 21552659. The next prime is 21552673. The reversal of 21552667 is 76625512.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21552667 - 2³ = 21552659 is a prime.

It is equal to p_1362697 and since 21552667 and 1362697 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (21552607) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10776333 + 10776334.

It is an arithmetic number, because the mean of its divisors is an integer number (10776334).

Almost surely, 2^21552667 is an apocalyptic number.

21552667 is a deficient number, since it is larger than the sum of its proper divisors (1).

21552667 is an equidigital number, since it uses as much as digits as its factorization.

21552667 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 25200, while the sum is 34.

The square root of 21552667 is about 4642.4850026683. The cubic root of 21552667 is about 278.2917550173.

The spelling of 21552667 in words is "twenty-one million, five hundred fifty-two thousand, six hundred sixty-seven".