21140069 has 2 divisors, whose sum is σ = 21140070. Its totient is φ = 21140068.

The previous prime is 21140033. The next prime is 21140089. The reversal of 21140069 is 96004112.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14915044 + 6225025 = 3862^2 + 2495^2 .

It is a cyclic number.

It is not a de Polignac number, because 21140069 - 2⁸ = 21139813 is a prime.

It is a super-2 number, since 2×21140069² = 893805034649522, 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 (21140089) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10570034 + 10570035.

It is an arithmetic number, because the mean of its divisors is an integer number (10570035).

Almost surely, 2^21140069 is an apocalyptic number.

It is an amenable number.

21140069 is a deficient number, since it is larger than the sum of its proper divisors (1).

21140069 is an equidigital number, since it uses as much as digits as its factorization.

21140069 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 432, while the sum is 23.

The square root of 21140069 is about 4597.8330765699. The cubic root of 21140069 is about 276.5044553236.

The spelling of 21140069 in words is "twenty-one million, one hundred forty thousand, sixty-nine".