20147251 has 2 divisors, whose sum is σ = 20147252. Its totient is φ = 20147250.

The previous prime is 20147221. The next prime is 20147273. The reversal of 20147251 is 15274102.

It is a happy number.

It is an a-pointer prime, because the next prime (20147273) can be obtained adding 20147251 to its sum of digits (22).

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20147251 - 2²¹ = 18050099 is a prime.

It is not a weakly prime, because it can be changed into another prime (20147221) 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 as a sum of consecutive naturals, namely, 10073625 + 10073626.

It is an arithmetic number, because the mean of its divisors is an integer number (10073626).

Almost surely, 2^20147251 is an apocalyptic number.

20147251 is a deficient number, since it is larger than the sum of its proper divisors (1).

20147251 is an equidigital number, since it uses as much as digits as its factorization.

20147251 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 560, while the sum is 22.

The square root of 20147251 is about 4488.5689256154. The cubic root of 20147251 is about 272.1063012635.

The spelling of 20147251 in words is "twenty million, one hundred forty-seven thousand, two hundred fifty-one".