20392281 has 36 divisors (see below), whose sum is σ = 36910692. Its totient is φ = 10753344.

The previous prime is 20392279. The next prime is 20392297. The reversal of 20392281 is 18229302.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 2752281 + 17640000 = 1659^2 + 4200^2 .

It is not a de Polignac number, because 20392281 - 2¹ = 20392279 is a prime.

It is a super-2 number, since 2×20392281² = 831690248765922, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20392201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 3955 + ... + 7511.

It is an arithmetic number, because the mean of its divisors is an integer number (1025297).

Almost surely, 2^20392281 is an apocalyptic number.

20392281 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

20392281 is a deficient number, since it is larger than the sum of its proper divisors (16518411).

20392281 is a wasteful number, since it uses less digits than its factorization.

20392281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3590 (or 3580 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 20392281 is about 4515.7813277438. The cubic root of 20392281 is about 273.2049742675.

The spelling of 20392281 in words is "twenty million, three hundred ninety-two thousand, two hundred eighty-one".