216745810 has 16 divisors (see below), whose sum is σ = 396539352. Its totient is φ = 85276800.

The previous prime is 216745807. The next prime is 216745819. The reversal of 216745810 is 18547612.

It can be written as a sum of positive squares in 4 ways, for example, as 178516321 + 38229489 = 13361^2 + 6183^2 .

It is a super-2 number, since 2×216745810² = 93957492305112200, which contains 22 as substring.

It is an alternating number because its digits alternate between even and odd.

It is not an unprimeable number, because it can be changed into a prime (216745819) 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, 177051 + ... + 178270.

Almost surely, 2^216745810 is an apocalyptic number.

216745810 is a deficient number, since it is larger than the sum of its proper divisors (179793542).

216745810 is a wasteful number, since it uses less digits than its factorization.

216745810 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 355389.

The product of its (nonzero) digits is 13440, while the sum is 34.

The square root of 216745810 is about 14722.2895637873. The cubic root of 216745810 is about 600.6897715363.

The spelling of 216745810 in words is "two hundred sixteen million, seven hundred forty-five thousand, eight hundred ten".