21070869 has 4 divisors (see below), whose sum is σ = 28094496. Its totient is φ = 14047244.

The previous prime is 21070859. The next prime is 21070873. The reversal of 21070869 is 96807012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21070869 - 2⁴ = 21070853 is a prime.

It is a super-2 number, since 2×21070869² = 887963040830322, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21070859) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3511809 + ... + 3511814.

It is an arithmetic number, because the mean of its divisors is an integer number (7023624).

Almost surely, 2^21070869 is an apocalyptic number.

It is an amenable number.

21070869 is a deficient number, since it is larger than the sum of its proper divisors (7023627).

21070869 is an equidigital number, since it uses as much as digits as its factorization.

21070869 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7023626.

The product of its (nonzero) digits is 6048, while the sum is 33.

The square root of 21070869 is about 4590.3016240766. The cubic root of 21070869 is about 276.2024218683.

The spelling of 21070869 in words is "twenty-one million, seventy thousand, eight hundred sixty-nine".