216871947 has 48 divisors (see below), whose sum is σ = 345290400. Its totient is φ = 130636800.

The previous prime is 216871937. The next prime is 216871951. The reversal of 216871947 is 749178612.

It is a happy number.

216871947 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 216871947 - 2⁶ = 216871883 is a prime.

Its product of digits (169344) is a multiple of the sum of its prime factors (588).

It is not an unprimeable number, because it can be changed into a prime (216871937) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 500643 + ... + 501075.

It is an arithmetic number, because the mean of its divisors is an integer number (7193550).

Almost surely, 2^216871947 is an apocalyptic number.

216871947 is a deficient number, since it is larger than the sum of its proper divisors (128418453).

216871947 is a wasteful number, since it uses less digits than its factorization.

216871947 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 588 (or 585 counting only the distinct ones).

The product of its digits is 169344, while the sum is 45.

The square root of 216871947 is about 14726.5728192272. The cubic root of 216871947 is about 600.8062743840.

The spelling of 216871947 in words is "two hundred sixteen million, eight hundred seventy-one thousand, nine hundred forty-seven".