20491331 has 8 divisors (see below), whose sum is σ = 23555424. Its totient is φ = 17461440.

The previous prime is 20491327. The next prime is 20491343. The reversal of 20491331 is 13319402.

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

It is a cyclic number.

It is not a de Polignac number, because 20491331 - 2² = 20491327 is a prime.

It is a super-2 number, since 2×20491331² = 839789292303122, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20491297 and 20491306.

It is not an unprimeable number, because it can be changed into a prime (20491301) 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 7 ways as a sum of consecutive naturals, for example, 7250 + ... + 9671.

It is an arithmetic number, because the mean of its divisors is an integer number (2944428).

Almost surely, 2^20491331 is an apocalyptic number.

20491331 is a deficient number, since it is larger than the sum of its proper divisors (3064093).

20491331 is a wasteful number, since it uses less digits than its factorization.

20491331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17101.

The product of its (nonzero) digits is 648, while the sum is 23.

The square root of 20491331 is about 4526.7351369392. The cubic root of 20491331 is about 273.6465998152.

The spelling of 20491331 in words is "twenty million, four hundred ninety-one thousand, three hundred thirty-one".