20491493 has 8 divisors (see below), whose sum is σ = 22407840. Its totient is φ = 18584080.

The previous prime is 20491489. The next prime is 20491561. The reversal of 20491493 is 39419402.

It is a happy number.

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 20491493 - 2² = 20491489 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 (20491433) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3143 + ... + 7131.

It is an arithmetic number, because the mean of its divisors is an integer number (2800980).

Almost surely, 2^20491493 is an apocalyptic number.

It is an amenable number.

20491493 is a deficient number, since it is larger than the sum of its proper divisors (1916347).

20491493 is a wasteful number, since it uses less digits than its factorization.

20491493 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4467.

The product of its (nonzero) digits is 7776, while the sum is 32.

The square root of 20491493 is about 4526.7530305949. The cubic root of 20491493 is about 273.6473209434.

The spelling of 20491493 in words is "twenty million, four hundred ninety-one thousand, four hundred ninety-three".