20988135 has 24 divisors (see below), whose sum is σ = 41577120. Its totient is φ = 9594432.

The previous prime is 20988133. The next prime is 20988161. The reversal of 20988135 is 53188902.

It is not a de Polignac number, because 20988135 - 2¹ = 20988133 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20988135.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20988131) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 33000 + ... + 33629.

It is an arithmetic number, because the mean of its divisors is an integer number (1732380).

Almost surely, 2^20988135 is an apocalyptic number.

20988135 is a deficient number, since it is larger than the sum of its proper divisors (20588985).

20988135 is a wasteful number, since it uses less digits than its factorization.

20988135 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66647 (or 66644 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 36.

The square root of 20988135 is about 4581.2809344112. The cubic root of 20988135 is about 275.8404481106.

The spelling of 20988135 in words is "twenty million, nine hundred eighty-eight thousand, one hundred thirty-five".