201661567 has 2 divisors, whose sum is σ = 201661568. Its totient is φ = 201661566.

The previous prime is 201661553. The next prime is 201661571. The reversal of 201661567 is 765166102.

It is a happy number.

201661567 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-201661567 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (201661597) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 100830783 + 100830784.

It is an arithmetic number, because the mean of its divisors is an integer number (100830784).

Almost surely, 2^201661567 is an apocalyptic number.

201661567 is a deficient number, since it is larger than the sum of its proper divisors (1).

201661567 is an equidigital number, since it uses as much as digits as its factorization.

201661567 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 15120, while the sum is 34.

The square root of 201661567 is about 14200.7593811035. The cubic root of 201661567 is about 586.4185672204.

The spelling of 201661567 in words is "two hundred one million, six hundred sixty-one thousand, five hundred sixty-seven".