216171557 has 12 divisors (see below), whose sum is σ = 253239648. Its totient is φ = 180760800.

The previous prime is 216171533. The next prime is 216171563. The reversal of 216171557 is 755171612.

It is not a de Polignac number, because 216171557 - 2⁸ = 216171301 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216171257) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2582 + ... + 20952.

It is an arithmetic number, because the mean of its divisors is an integer number (21103304).

Almost surely, 2^216171557 is an apocalyptic number.

It is an amenable number.

216171557 is a deficient number, since it is larger than the sum of its proper divisors (37068091).

216171557 is an equidigital number, since it uses as much as digits as its factorization.

216171557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18460 (or 18419 counting only the distinct ones).

The product of its digits is 14700, while the sum is 35.

The square root of 216171557 is about 14702.7737859222. The cubic root of 216171557 is about 600.1588070376.

The spelling of 216171557 in words is "two hundred sixteen million, one hundred seventy-one thousand, five hundred fifty-seven".