21100069 has 2 divisors, whose sum is σ = 21100070. Its totient is φ = 21100068.

The previous prime is 21100063. The next prime is 21100087. The reversal of 21100069 is 96000112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19695844 + 1404225 = 4438^2 + 1185^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21100069 is a prime.

It is a super-2 number, since 2×21100069² = 890425823609522, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21100063) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10550034 + 10550035.

It is an arithmetic number, because the mean of its divisors is an integer number (10550035).

Almost surely, 2^21100069 is an apocalyptic number.

It is an amenable number.

21100069 is a deficient number, since it is larger than the sum of its proper divisors (1).

21100069 is an equidigital number, since it uses as much as digits as its factorization.

21100069 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 108, while the sum is 19.

The square root of 21100069 is about 4593.4811417921. The cubic root of 21100069 is about 276.3299500375.

The spelling of 21100069 in words is "twenty-one million, one hundred thousand, sixty-nine".