20147281 has 12 divisors (see below), whose sum is σ = 25567920. Its totient is φ = 15698760.

The previous prime is 20147273. The next prime is 20147297. The reversal of 20147281 is 18274102.

It is a happy number.

It is not a de Polignac number, because 20147281 - 2³ = 20147273 is a prime.

It is a super-2 number, since 2×20147281² = 811825863385922, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20147221) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 18151 + ... + 19228.

It is an arithmetic number, because the mean of its divisors is an integer number (2130660).

Almost surely, 2^20147281 is an apocalyptic number.

It is an amenable number.

20147281 is a deficient number, since it is larger than the sum of its proper divisors (5420639).

20147281 is a wasteful number, since it uses less digits than its factorization.

20147281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37404 (or 37397 counting only the distinct ones).

The product of its (nonzero) digits is 896, while the sum is 25.

The square root of 20147281 is about 4488.5722674365. The cubic root of 20147281 is about 272.1064363222.

The spelling of 20147281 in words is "twenty million, one hundred forty-seven thousand, two hundred eighty-one".