21657067 has 2 divisors, whose sum is σ = 21657068. Its totient is φ = 21657066.

The previous prime is 21657049. The next prime is 21657137. The reversal of 21657067 is 76075612.

21657067 is nontrivially palindromic in base 12.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21657067 is a prime.

It is not a weakly prime, because it can be changed into another prime (21657367) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10828533 + 10828534.

It is an arithmetic number, because the mean of its divisors is an integer number (10828534).

Almost surely, 2^21657067 is an apocalyptic number.

21657067 is a deficient number, since it is larger than the sum of its proper divisors (1).

21657067 is an equidigital number, since it uses as much as digits as its factorization.

21657067 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 17640, while the sum is 34.

The square root of 21657067 is about 4653.7153974002. The cubic root of 21657067 is about 278.7403750355.

The spelling of 21657067 in words is "twenty-one million, six hundred fifty-seven thousand, sixty-seven".