21159769 has 4 divisors (see below), whose sum is σ = 21278160. Its totient is φ = 21041380.

The previous prime is 21159757. The next prime is 21159779. The reversal of 21159769 is 96795112.

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 21159769 - 2⁵ = 21159737 is a prime.

It is a super-2 number, since 2×21159769² = 895471648266722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21159709) 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, 58927 + ... + 59284.

It is an arithmetic number, because the mean of its divisors is an integer number (5319540).

Almost surely, 2^21159769 is an apocalyptic number.

It is an amenable number.

21159769 is a deficient number, since it is larger than the sum of its proper divisors (118391).

21159769 is a wasteful number, since it uses less digits than its factorization.

21159769 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 118390.

The product of its digits is 34020, while the sum is 40.

The square root of 21159769 is about 4599.9748912358. The cubic root of 21159769 is about 276.5903182824.

The spelling of 21159769 in words is "twenty-one million, one hundred fifty-nine thousand, seven hundred sixty-nine".