20986623 has 48 divisors (see below), whose sum is σ = 36315136. Its totient is φ = 11430720.

The previous prime is 20986613. The next prime is 20986631. The reversal of 20986623 is 32668902.

20986623 is a `hidden beast` number, since 20 + 9 + 8 + 6 + 623 = 666.

It is not a de Polignac number, because 20986623 - 2¹³ = 20978431 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20986613) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 165186 + ... + 165312.

Almost surely, 2^20986623 is an apocalyptic number.

20986623 is a deficient number, since it is larger than the sum of its proper divisors (15328513).

20986623 is a wasteful number, since it uses less digits than its factorization.

20986623 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 244 (or 241 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 36.

The square root of 20986623 is about 4581.1159120895. The cubic root of 20986623 is about 275.8338240383.

It can be divided in two parts, 20986 and 623, that added together give a square (21609 = 147²).

The spelling of 20986623 in words is "twenty million, nine hundred eighty-six thousand, six hundred twenty-three".