20152281 has 4 divisors (see below), whose sum is σ = 26869712. Its totient is φ = 13434852.

The previous prime is 20152277. The next prime is 20152291. The reversal of 20152281 is 18225102.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 20152281 - 2² = 20152277 is a prime.

It is a super-2 number, since 2×20152281² = 812228859005922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20152211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3358711 + ... + 3358716.

It is an arithmetic number, because the mean of its divisors is an integer number (6717428).

Almost surely, 2^20152281 is an apocalyptic number.

It is an amenable number.

20152281 is a deficient number, since it is larger than the sum of its proper divisors (6717431).

20152281 is an equidigital number, since it uses as much as digits as its factorization.

20152281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6717430.

The product of its (nonzero) digits is 320, while the sum is 21.

The square root of 20152281 is about 4489.1292028633. The cubic root of 20152281 is about 272.1289442336.

Adding to 20152281 its reverse (18225102), we get a palindrome (38377383).

The spelling of 20152281 in words is "twenty million, one hundred fifty-two thousand, two hundred eighty-one".