20523817 has 2 divisors, whose sum is σ = 20523818. Its totient is φ = 20523816.

The previous prime is 20523809. The next prime is 20523827. The reversal of 20523817 is 71832502.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11397376 + 9126441 = 3376^2 + 3021^2 .

It is a cyclic number.

It is not a de Polignac number, because 20523817 - 2³ = 20523809 is a prime.

It is not a weakly prime, because it can be changed into another prime (20523827) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10261908 + 10261909.

It is an arithmetic number, because the mean of its divisors is an integer number (10261909).

Almost surely, 2^20523817 is an apocalyptic number.

It is an amenable number.

20523817 is a deficient number, since it is larger than the sum of its proper divisors (1).

20523817 is an equidigital number, since it uses as much as digits as its factorization.

20523817 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 20523817 is about 4530.3219532391. The cubic root of 20523817 is about 273.7911323138.

The spelling of 20523817 in words is "twenty million, five hundred twenty-three thousand, eight hundred seventeen".