20988669 has 16 divisors (see below), whose sum is σ = 30252992. Its totient is φ = 12866688.

The previous prime is 20988637. The next prime is 20988677. The reversal of 20988669 is 96688902.

It is not a de Polignac number, because 20988669 - 2⁵ = 20988637 is a prime.

It is a super-2 number, since 2×20988669² = 881048452783122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20988629) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11097 + ... + 12849.

It is an arithmetic number, because the mean of its divisors is an integer number (1890812).

Almost surely, 2^20988669 is an apocalyptic number.

It is an amenable number.

20988669 is a deficient number, since it is larger than the sum of its proper divisors (9264323).

20988669 is a wasteful number, since it uses less digits than its factorization.

20988669 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2076.

The product of its (nonzero) digits is 373248, while the sum is 48.

The square root of 20988669 is about 4581.3392146838. The cubic root of 20988669 is about 275.8427874887.

The spelling of 20988669 in words is "twenty million, nine hundred eighty-eight thousand, six hundred sixty-nine".