20998065 has 16 divisors (see below), whose sum is σ = 36651456. Its totient is φ = 10180800.

The previous prime is 20998063. The next prime is 20998069. The reversal of 20998065 is 56089902.

It is a happy number.

It is not a de Polignac number, because 20998065 - 2¹ = 20998063 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20998063) 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, 63466 + ... + 63795.

It is an arithmetic number, because the mean of its divisors is an integer number (2290716).

Almost surely, 2^20998065 is an apocalyptic number.

It is an amenable number.

20998065 is a deficient number, since it is larger than the sum of its proper divisors (15653391).

20998065 is a wasteful number, since it uses less digits than its factorization.

20998065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 127280.

The product of its (nonzero) digits is 38880, while the sum is 39.

The square root of 20998065 is about 4582.3645642834. The cubic root of 20998065 is about 275.8839435393.

The spelling of 20998065 in words is "twenty million, nine hundred ninety-eight thousand, sixty-five".