20428730 has 32 divisors (see below), whose sum is σ = 44499456. Its totient is φ = 6591744.

The previous prime is 20428697. The next prime is 20428739. The reversal of 20428730 is 3782402.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 20428730.

It is not an unprimeable number, because it can be changed into a prime (20428739) 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 15 ways as a sum of consecutive naturals, for example, 7394 + ... + 9773.

It is an arithmetic number, because the mean of its divisors is an integer number (1390608).

Almost surely, 2^20428730 is an apocalyptic number.

20428730 is an abundant number, since it is smaller than the sum of its proper divisors (24070726).

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

20428730 is a wasteful number, since it uses less digits than its factorization.

20428730 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17198.

The product of its (nonzero) digits is 2688, while the sum is 26.

The square root of 20428730 is about 4519.8152617115. The cubic root of 20428730 is about 273.3676521784.

The spelling of 20428730 in words is "twenty million, four hundred twenty-eight thousand, seven hundred thirty".