216540829 has 4 divisors (see below), whose sum is σ = 216677020. Its totient is φ = 216404640.

The previous prime is 216540823. The next prime is 216540887. The reversal of 216540829 is 928045612.

216540829 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 212139225 + 4401604 = 14565^2 + 2098^2 .

It is a cyclic number.

It is not a de Polignac number, because 216540829 - 2¹³ = 216532637 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 (216540823) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 65682 + ... + 68899.

It is an arithmetic number, because the mean of its divisors is an integer number (54169255).

Almost surely, 2^216540829 is an apocalyptic number.

It is an amenable number.

216540829 is a deficient number, since it is larger than the sum of its proper divisors (136191).

216540829 is a wasteful number, since it uses less digits than its factorization.

216540829 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 136190.

The product of its (nonzero) digits is 34560, while the sum is 37.

The square root of 216540829 is about 14715.3263300547. The cubic root of 216540829 is about 600.5003502260.

The spelling of 216540829 in words is "two hundred sixteen million, five hundred forty thousand, eight hundred twenty-nine".