216879840 has 72 divisors (see below), whose sum is σ = 740107368. Its totient is φ = 57834240.

The previous prime is 216879823. The next prime is 216879841. The reversal of 216879840 is 48978612.

216879840 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (72).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216879841) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 73866 + ... + 76745.

It is an arithmetic number, because the mean of its divisors is an integer number (10279269).

Almost surely, 2^216879840 is an apocalyptic number.

216879840 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

216879840 is an abundant number, since it is smaller than the sum of its proper divisors (523227528).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

216879840 is a wasteful number, since it uses less digits than its factorization.

216879840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 150632 (or 150621 counting only the distinct ones).

The product of its (nonzero) digits is 193536, while the sum is 45.

The square root of 216879840 is about 14726.8408017470. The cubic root of 216879840 is about 600.8135630267.

The spelling of 216879840 in words is "two hundred sixteen million, eight hundred seventy-nine thousand, eight hundred forty".