20991127 has 8 divisors (see below), whose sum is σ = 21455280. Its totient is φ = 20529600.

The previous prime is 20991121. The next prime is 20991149. The reversal of 20991127 is 72119902.

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-20991127 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 (20991121) 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, 31524 + ... + 32182.

It is an arithmetic number, because the mean of its divisors is an integer number (2681910).

Almost surely, 2^20991127 is an apocalyptic number.

20991127 is a deficient number, since it is larger than the sum of its proper divisors (464153).

20991127 is an equidigital number, since it uses as much as digits as its factorization.

20991127 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1313.

The product of its (nonzero) digits is 2268, while the sum is 31.

The square root of 20991127 is about 4581.6074690004. The cubic root of 20991127 is about 275.8535551257.

The spelling of 20991127 in words is "twenty million, nine hundred ninety-one thousand, one hundred twenty-seven".