20587513 has 2 divisors, whose sum is σ = 20587514. Its totient is φ = 20587512.

The previous prime is 20587487. The next prime is 20587517. The reversal of 20587513 is 31578502.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10778089 + 9809424 = 3283^2 + 3132^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20587513 is a prime.

It is not a weakly prime, because it can be changed into another prime (20587517) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10293756 + 10293757.

It is an arithmetic number, because the mean of its divisors is an integer number (10293757).

Almost surely, 2^20587513 is an apocalyptic number.

It is an amenable number.

20587513 is a deficient number, since it is larger than the sum of its proper divisors (1).

20587513 is an equidigital number, since it uses as much as digits as its factorization.

20587513 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8400, while the sum is 31.

The square root of 20587513 is about 4537.3464712318. The cubic root of 20587513 is about 274.0740782176.

The spelling of 20587513 in words is "twenty million, five hundred eighty-seven thousand, five hundred thirteen".