216540831 has 8 divisors (see below), whose sum is σ = 310930480. Its totient is φ = 133255872.

The previous prime is 216540823. The next prime is 216540887. The reversal of 216540831 is 138045612.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 216540831 - 2³ = 216540823 is a prime.

It is a super-2 number, since 2×216540831² = 93779862980341122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216540811) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2776126 + ... + 2776203.

It is an arithmetic number, because the mean of its divisors is an integer number (38866310).

Almost surely, 2^216540831 is an apocalyptic number.

216540831 is a deficient number, since it is larger than the sum of its proper divisors (94389649).

216540831 is a wasteful number, since it uses less digits than its factorization.

216540831 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5552345.

The product of its (nonzero) digits is 5760, while the sum is 30.

The square root of 216540831 is about 14715.3263980110. The cubic root of 216540831 is about 600.5003520748.

The spelling of 216540831 in words is "two hundred sixteen million, five hundred forty thousand, eight hundred thirty-one".