21050769 has 4 divisors (see below), whose sum is σ = 28067696. Its totient is φ = 14033844.

The previous prime is 21050749. The next prime is 21050801. The reversal of 21050769 is 96705012.

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 not a de Polignac number, because 21050769 - 2⁵ = 21050737 is a prime.

It is a super-2 number, since 2×21050769² = 886269750982722, which contains 22 as substring.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21050749) 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, 3508459 + ... + 3508464.

It is an arithmetic number, because the mean of its divisors is an integer number (7016924).

Almost surely, 2^21050769 is an apocalyptic number.

It is an amenable number.

21050769 is a deficient number, since it is larger than the sum of its proper divisors (7016927).

21050769 is an equidigital number, since it uses as much as digits as its factorization.

21050769 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7016926.

The product of its (nonzero) digits is 3780, while the sum is 30.

The square root of 21050769 is about 4588.1117030866. Note that the first 3 decimals coincide. The cubic root of 21050769 is about 276.1145685877.

The spelling of 21050769 in words is "twenty-one million, fifty thousand, seven hundred sixty-nine".