20789381 has 4 divisors (see below), whose sum is σ = 20897292. Its totient is φ = 20681472.

The previous prime is 20789371. The next prime is 20789393. The reversal of 20789381 is 18398702.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 5313025 + 15476356 = 2305^2 + 3934^2 .

It is a cyclic number.

It is not a de Polignac number, because 20789381 - 2¹⁰ = 20788357 is a prime.

It is a super-2 number, since 2×20789381² = 864396724726322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20789311) 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, 53666 + ... + 54051.

It is an arithmetic number, because the mean of its divisors is an integer number (5224323).

Almost surely, 2^20789381 is an apocalyptic number.

It is an amenable number.

20789381 is a deficient number, since it is larger than the sum of its proper divisors (107911).

20789381 is a wasteful number, since it uses less digits than its factorization.

20789381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 107910.

The product of its (nonzero) digits is 24192, while the sum is 38.

The square root of 20789381 is about 4559.5373668827. The cubic root of 20789381 is about 274.9669646267.

The spelling of 20789381 in words is "twenty million, seven hundred eighty-nine thousand, three hundred eighty-one".