21052069 has 16 divisors (see below), whose sum is σ = 23569920. Its totient is φ = 18708480.

The previous prime is 21052063. The next prime is 21052079. The reversal of 21052069 is 96025012.

It is a cyclic number.

It is not a de Polignac number, because 21052069 - 2²¹ = 18954917 is a prime.

It is a super-2 number, since 2×21052069² = 886379218361522, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21052063) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 22197 + ... + 23125.

It is an arithmetic number, because the mean of its divisors is an integer number (1473120).

Almost surely, 2^21052069 is an apocalyptic number.

It is an amenable number.

21052069 is a deficient number, since it is larger than the sum of its proper divisors (2517851).

21052069 is a wasteful number, since it uses less digits than its factorization.

21052069 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1020.

The product of its (nonzero) digits is 1080, while the sum is 25.

The square root of 21052069 is about 4588.2533713822. The cubic root of 21052069 is about 276.1202523317.

The spelling of 21052069 in words is "twenty-one million, fifty-two thousand, sixty-nine".