201661558 has 24 divisors (see below), whose sum is σ = 357142392. Its totient is φ = 85133664.

The previous prime is 201661553. The next prime is 201661567. The reversal of 201661558 is 855166102.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (201661553) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8791 + ... + 21922.

It is an arithmetic number, because the mean of its divisors is an integer number (14880933).

Almost surely, 2^201661558 is an apocalyptic number.

201661558 is a deficient number, since it is larger than the sum of its proper divisors (155480834).

201661558 is a wasteful number, since it uses less digits than its factorization.

201661558 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30796 (or 30789 counting only the distinct ones).

The product of its (nonzero) digits is 14400, while the sum is 34.

The square root of 201661558 is about 14200.7590642191. The cubic root of 201661558 is about 586.4185584966.

The spelling of 201661558 in words is "two hundred one million, six hundred sixty-one thousand, five hundred fifty-eight".