20571601 has 2 divisors, whose sum is σ = 20571602. Its totient is φ = 20571600.

The previous prime is 20571599. The next prime is 20571641. The reversal of 20571601 is 10617502.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15992001 + 4579600 = 3999^2 + 2140^2 .

It is a cyclic number.

It is not a de Polignac number, because 20571601 - 2¹ = 20571599 is a prime.

Together with 20571599, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (20571641) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10285800 + 10285801.

It is an arithmetic number, because the mean of its divisors is an integer number (10285801).

Almost surely, 2^20571601 is an apocalyptic number.

It is an amenable number.

20571601 is a deficient number, since it is larger than the sum of its proper divisors (1).

20571601 is an equidigital number, since it uses as much as digits as its factorization.

20571601 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 420, while the sum is 22.

The square root of 20571601 is about 4535.5926845342. The cubic root of 20571601 is about 274.0034497941.

The spelling of 20571601 in words is "twenty million, five hundred seventy-one thousand, six hundred one".