20870513 has 2 divisors, whose sum is σ = 20870514. Its totient is φ = 20870512.

The previous prime is 20870503. The next prime is 20870573. The reversal of 20870513 is 31507802.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13778944 + 7091569 = 3712^2 + 2663^2 .

It is a cyclic number.

It is not a de Polignac number, because 20870513 - 2⁴ = 20870497 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (20870503) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10435256 + 10435257.

It is an arithmetic number, because the mean of its divisors is an integer number (10435257).

Almost surely, 2^20870513 is an apocalyptic number.

It is an amenable number.

20870513 is a deficient number, since it is larger than the sum of its proper divisors (1).

20870513 is an equidigital number, since it uses as much as digits as its factorization.

20870513 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1680, while the sum is 26.

The square root of 20870513 is about 4568.4256588019. The cubic root of 20870513 is about 275.3241928709.

The spelling of 20870513 in words is "twenty million, eight hundred seventy thousand, five hundred thirteen".