20901281 has 4 divisors (see below), whose sum is σ = 21255600. Its totient is φ = 20546964.

The previous prime is 20901277. The next prime is 20901289. The reversal of 20901281 is 18210902.

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 a cyclic number.

It is not a de Polignac number, because 20901281 - 2² = 20901277 is a prime.

It is a super-2 number, since 2×20901281² = 873727094881922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20901289) 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, 177071 + ... + 177188.

It is an arithmetic number, because the mean of its divisors is an integer number (5313900).

Almost surely, 2^20901281 is an apocalyptic number.

It is an amenable number.

20901281 is a deficient number, since it is larger than the sum of its proper divisors (354319).

20901281 is an equidigital number, since it uses as much as digits as its factorization.

20901281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 354318.

The product of its (nonzero) digits is 288, while the sum is 23.

The square root of 20901281 is about 4571.7918806525. The cubic root of 20901281 is about 275.4594237801.

The spelling of 20901281 in words is "twenty million, nine hundred one thousand, two hundred eighty-one".