20730428 has 12 divisors (see below), whose sum is σ = 36332520. Its totient is φ = 10349712.

The previous prime is 20730421. The next prime is 20730433. The reversal of 20730428 is 82403702.

20730428 is nontrivially palindromic in base 13.

It is a junction number, because it is equal to n+sod(n) for n = 20730397 and 20730406.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20730421) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 551 + ... + 6462.

It is an arithmetic number, because the mean of its divisors is an integer number (3027710).

Almost surely, 2^20730428 is an apocalyptic number.

It is an amenable number.

20730428 is a deficient number, since it is larger than the sum of its proper divisors (15602092).

20730428 is a wasteful number, since it uses less digits than its factorization.

20730428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7756 (or 7754 counting only the distinct ones).

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

The square root of 20730428 is about 4553.0679766505. The cubic root of 20730428 is about 274.7068081852.

The spelling of 20730428 in words is "twenty million, seven hundred thirty thousand, four hundred twenty-eight".