20997494 has 32 divisors (see below), whose sum is σ = 37267776. Its totient is φ = 8686080.

The previous prime is 20997491. The next prime is 20997511. The reversal of 20997494 is 49479902.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20997491) 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 15 ways as a sum of consecutive naturals, for example, 90002 + ... + 90234.

It is an arithmetic number, because the mean of its divisors is an integer number (1164618).

Almost surely, 2^20997494 is an apocalyptic number.

20997494 is a deficient number, since it is larger than the sum of its proper divisors (16270282).

20997494 is a wasteful number, since it uses less digits than its factorization.

20997494 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 440.

The product of its (nonzero) digits is 163296, while the sum is 44.

The square root of 20997494 is about 4582.3022597816. The cubic root of 20997494 is about 275.8814428143.

The spelling of 20997494 in words is "twenty million, nine hundred ninety-seven thousand, four hundred ninety-four".