20909769 has 4 divisors (see below), whose sum is σ = 27879696. Its totient is φ = 13939844.

The previous prime is 20909767. The next prime is 20909771. The reversal of 20909769 is 96790902.

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 an interprime number because it is at equal distance from previous prime (20909767) and next prime (20909771).

It is a cyclic number.

It is not a de Polignac number, because 20909769 - 2¹ = 20909767 is a prime.

It is a super-2 number, since 2×20909769² = 874436879266722, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20909769.

It is not an unprimeable number, because it can be changed into a prime (20909767) 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, 3484959 + ... + 3484964.

It is an arithmetic number, because the mean of its divisors is an integer number (6969924).

Almost surely, 2^20909769 is an apocalyptic number.

It is an amenable number.

20909769 is a deficient number, since it is larger than the sum of its proper divisors (6969927).

20909769 is an equidigital number, since it uses as much as digits as its factorization.

20909769 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6969926.

The product of its (nonzero) digits is 61236, while the sum is 42.

The square root of 20909769 is about 4572.7200876502. The cubic root of 20909769 is about 275.4967067128.

The spelling of 20909769 in words is "twenty million, nine hundred nine thousand, seven hundred sixty-nine".