20147539 has 2 divisors, whose sum is σ = 20147540. Its totient is φ = 20147538.

The previous prime is 20147509. The next prime is 20147549. The reversal of 20147539 is 93574102.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20147539 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20147539.

It is not a weakly prime, because it can be changed into another prime (20147509) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10073769 + 10073770.

It is an arithmetic number, because the mean of its divisors is an integer number (10073770).

Almost surely, 2^20147539 is an apocalyptic number.

20147539 is a deficient number, since it is larger than the sum of its proper divisors (1).

20147539 is an equidigital number, since it uses as much as digits as its factorization.

20147539 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7560, while the sum is 31.

The square root of 20147539 is about 4488.6010069954. The cubic root of 20147539 is about 272.1075978215.

The spelling of 20147539 in words is "twenty million, one hundred forty-seven thousand, five hundred thirty-nine".