20489784 has 32 divisors (see below), whose sum is σ = 58542720. Its totient is φ = 5854176.

The previous prime is 20489779. The next prime is 20489789. The reversal of 20489784 is 48798402.

It is an interprime number because it is at equal distance from previous prime (20489779) and next prime (20489789).

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20489789) 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, 60814 + ... + 61149.

It is an arithmetic number, because the mean of its divisors is an integer number (1829460).

Almost surely, 2^20489784 is an apocalyptic number.

20489784 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

20489784 is an abundant number, since it is smaller than the sum of its proper divisors (38052936).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20489784 is a wasteful number, since it uses less digits than its factorization.

20489784 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 121979 (or 121975 counting only the distinct ones).

The product of its (nonzero) digits is 129024, while the sum is 42.

The square root of 20489784 is about 4526.5642600100. The cubic root of 20489784 is about 273.6397132942.

The spelling of 20489784 in words is "twenty million, four hundred eighty-nine thousand, seven hundred eighty-four".