20939553 has 12 divisors (see below), whose sum is σ = 31366608. Its totient is φ = 13959540.

The previous prime is 20939543. The next prime is 20939557. The reversal of 20939553 is 35593902.

It is not a de Polignac number, because 20939553 - 2¹⁰ = 20938529 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20939557) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 42843 + ... + 43328.

It is an arithmetic number, because the mean of its divisors is an integer number (2613884).

Almost surely, 2^20939553 is an apocalyptic number.

It is an amenable number.

20939553 is a deficient number, since it is larger than the sum of its proper divisors (10427055).

20939553 is an frugal number, since it uses more digits than its factorization.

20939553 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86186 (or 86174 counting only the distinct ones).

The product of its (nonzero) digits is 36450, while the sum is 36.

The square root of 20939553 is about 4575.9756336764. The cubic root of 20939553 is about 275.6274510403.

The spelling of 20939553 in words is "twenty million, nine hundred thirty-nine thousand, five hundred fifty-three".