20379281 has 4 divisors (see below), whose sum is σ = 21946932. Its totient is φ = 18811632.

The previous prime is 20379259. The next prime is 20379283. The reversal of 20379281 is 18297302.

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 11498881 + 8880400 = 3391^2 + 2980^2 .

It is a cyclic number.

It is not a de Polignac number, because 20379281 - 2⁶ = 20379217 is a prime.

It is a super-2 number, since 2×20379281² = 830630188153922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20379283) 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, 783806 + ... + 783831.

It is an arithmetic number, because the mean of its divisors is an integer number (5486733).

Almost surely, 2^20379281 is an apocalyptic number.

It is an amenable number.

20379281 is a deficient number, since it is larger than the sum of its proper divisors (1567651).

20379281 is a wasteful number, since it uses less digits than its factorization.

20379281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1567650.

The product of its (nonzero) digits is 6048, while the sum is 32.

The square root of 20379281 is about 4514.3417017324. The cubic root of 20379281 is about 273.1469062228.

The spelling of 20379281 in words is "twenty million, three hundred seventy-nine thousand, two hundred eighty-one".