21157067 has 2 divisors, whose sum is σ = 21157068. Its totient is φ = 21157066.

The previous prime is 21157049. The next prime is 21157091. The reversal of 21157067 is 76075112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21157067 - 2¹⁴ = 21140683 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21157267) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10578533 + 10578534.

It is an arithmetic number, because the mean of its divisors is an integer number (10578534).

Almost surely, 2^21157067 is an apocalyptic number.

21157067 is a deficient number, since it is larger than the sum of its proper divisors (1).

21157067 is an equidigital number, since it uses as much as digits as its factorization.

21157067 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2940, while the sum is 29.

The square root of 21157067 is about 4599.6811846040. The cubic root of 21157067 is about 276.5785446999.

The spelling of 21157067 in words is "twenty-one million, one hundred fifty-seven thousand, sixty-seven".