20720284 has 12 divisors (see below), whose sum is σ = 39049864. Its totient is φ = 9563184.

The previous prime is 20720261. The next prime is 20720299. The reversal of 20720284 is 48202702.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 199182 + ... + 199285.

Almost surely, 2^20720284 is an apocalyptic number.

It is an amenable number.

20720284 is a deficient number, since it is larger than the sum of its proper divisors (18329580).

20720284 is a wasteful number, since it uses less digits than its factorization.

20720284 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 398484 (or 398482 counting only the distinct ones).

The product of its (nonzero) digits is 1792, while the sum is 25.

The square root of 20720284 is about 4551.9538661986. The cubic root of 20720284 is about 274.6619935370.

Adding to 20720284 its reverse (48202702), we get a palindrome (68922986).

The spelling of 20720284 in words is "twenty million, seven hundred twenty thousand, two hundred eighty-four".