20881969 has 4 divisors (see below), whose sum is σ = 21981040. Its totient is φ = 19782900.

The previous prime is 20881963. The next prime is 20882009. The reversal of 20881969 is 96918802.

It is a happy number.

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 20881969 - 2¹¹ = 20879921 is a prime.

It is a super-2 number, since 2×20881969² = 872113258633922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20881963) 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, 549507 + ... + 549544.

It is an arithmetic number, because the mean of its divisors is an integer number (5495260).

Almost surely, 2^20881969 is an apocalyptic number.

It is an amenable number.

20881969 is a deficient number, since it is larger than the sum of its proper divisors (1099071).

20881969 is a wasteful number, since it uses less digits than its factorization.

20881969 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1099070.

The product of its (nonzero) digits is 62208, while the sum is 43.

The square root of 20881969 is about 4569.6793104112. The cubic root of 20881969 is about 275.3745595776.

The spelling of 20881969 in words is "twenty million, eight hundred eighty-one thousand, nine hundred sixty-nine".