216723531 has 8 divisors (see below), whose sum is σ = 305962704. Its totient is φ = 135983360.

The previous prime is 216723523. The next prime is 216723553. The reversal of 216723531 is 135327612.

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

It is a cyclic number.

It is not a de Polignac number, because 216723531 - 2³ = 216723523 is a prime.

It is a super-2 number, since 2×216723531² = 93938177778215922, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (216723431) 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, 2124690 + ... + 2124791.

It is an arithmetic number, because the mean of its divisors is an integer number (38245338).

Almost surely, 2^216723531 is an apocalyptic number.

216723531 is a deficient number, since it is larger than the sum of its proper divisors (89239173).

216723531 is a wasteful number, since it uses less digits than its factorization.

216723531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4249501.

The product of its digits is 7560, while the sum is 30.

The square root of 216723531 is about 14721.5329025207. The cubic root of 216723531 is about 600.6691894760.

The spelling of 216723531 in words is "two hundred sixteen million, seven hundred twenty-three thousand, five hundred thirty-one".