20902091 has 8 divisors (see below), whose sum is σ = 24658944. Its totient is φ = 17337960.

The previous prime is 20902081. The next prime is 20902103. The reversal of 20902091 is 19020902.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20902091 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20902031) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 47945 + ... + 48378.

It is an arithmetic number, because the mean of its divisors is an integer number (3082368).

Almost surely, 2^20902091 is an apocalyptic number.

20902091 is a deficient number, since it is larger than the sum of its proper divisors (3756853).

20902091 is an equidigital number, since it uses as much as digits as its factorization.

20902091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 96361.

The product of its (nonzero) digits is 324, while the sum is 23.

The square root of 20902091 is about 4571.8804665039. The cubic root of 20902091 is about 275.4629820827.

Adding to 20902091 its reverse (19020902), we get a palindrome (39922993).

The spelling of 20902091 in words is "twenty million, nine hundred two thousand, ninety-one".