20121087 has 16 divisors (see below), whose sum is σ = 30770432. Its totient is φ = 11456640.

The previous prime is 20121061. The next prime is 20121091. The reversal of 20121087 is 78012102.

It is not a de Polignac number, because 20121087 - 2⁷ = 20120959 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20121097) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4887 + ... + 8007.

It is an arithmetic number, because the mean of its divisors is an integer number (1923152).

Almost surely, 2^20121087 is an apocalyptic number.

20121087 is a deficient number, since it is larger than the sum of its proper divisors (10649345).

20121087 is a wasteful number, since it uses less digits than its factorization.

20121087 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3438.

The product of its (nonzero) digits is 224, while the sum is 21.

The square root of 20121087 is about 4485.6534641009. The cubic root of 20121087 is about 271.9884609796.

Adding to 20121087 its reverse (78012102), we get a palindrome (98133189).

The spelling of 20121087 in words is "twenty million, one hundred twenty-one thousand, eighty-seven".