20782513 has 2 divisors, whose sum is σ = 20782514. Its totient is φ = 20782512.

The previous prime is 20782499. The next prime is 20782543. The reversal of 20782513 is 31528702.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20223009 + 559504 = 4497^2 + 748^2 .

It is a cyclic number.

It is not a de Polignac number, because 20782513 - 2¹³ = 20774321 is a prime.

It is not a weakly prime, because it can be changed into another prime (20782543) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10391256 + 10391257.

It is an arithmetic number, because the mean of its divisors is an integer number (10391257).

Almost surely, 2^20782513 is an apocalyptic number.

It is an amenable number.

20782513 is a deficient number, since it is larger than the sum of its proper divisors (1).

20782513 is an equidigital number, since it uses as much as digits as its factorization.

20782513 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3360, while the sum is 28.

The square root of 20782513 is about 4558.7841580843. The cubic root of 20782513 is about 274.9366818410.

The spelling of 20782513 in words is "twenty million, seven hundred eighty-two thousand, five hundred thirteen".