201661597 has 2 divisors, whose sum is σ = 201661598. Its totient is φ = 201661596.

The previous prime is 201661589. The next prime is 201661601. The reversal of 201661597 is 795166102.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 123409881 + 78251716 = 11109^2 + 8846^2 .

It is a cyclic number.

It is not a de Polignac number, because 201661597 - 2³ = 201661589 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (201661567) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 100830798 + 100830799.

It is an arithmetic number, because the mean of its divisors is an integer number (100830799).

Almost surely, 2^201661597 is an apocalyptic number.

It is an amenable number.

201661597 is a deficient number, since it is larger than the sum of its proper divisors (1).

201661597 is an equidigital number, since it uses as much as digits as its factorization.

201661597 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 22680, while the sum is 37.

The square root of 201661597 is about 14200.7604373850. The cubic root of 201661597 is about 586.4185962998.

The spelling of 201661597 in words is "two hundred one million, six hundred sixty-one thousand, five hundred ninety-seven".