20897493 has 4 divisors (see below), whose sum is σ = 27863328. Its totient is φ = 13931660.

The previous prime is 20897483. The next prime is 20897497. The reversal of 20897493 is 39479802.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20897493 - 2⁴ = 20897477 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20897497) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3482913 + ... + 3482918.

It is an arithmetic number, because the mean of its divisors is an integer number (6965832).

Almost surely, 2^20897493 is an apocalyptic number.

It is an amenable number.

20897493 is a deficient number, since it is larger than the sum of its proper divisors (6965835).

20897493 is an equidigital number, since it uses as much as digits as its factorization.

20897493 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6965834.

The product of its (nonzero) digits is 108864, while the sum is 42.

The square root of 20897493 is about 4571.3775823049. The cubic root of 20897493 is about 275.4427820036.

The spelling of 20897493 in words is "twenty million, eight hundred ninety-seven thousand, four hundred ninety-three".