216881889 has 12 divisors (see below), whose sum is σ = 336388464. Its totient is φ = 123932424.

The previous prime is 216881887. The next prime is 216881891. The reversal of 216881889 is 988188612.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (216881887) and next prime (216881891).

It is not a de Polignac number, because 216881889 - 2¹ = 216881887 is a prime.

It is not an unprimeable number, because it can be changed into a prime (216881887) 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, 737547 + ... + 737840.

It is an arithmetic number, because the mean of its divisors is an integer number (28032372).

Almost surely, 2^216881889 is an apocalyptic number.

It is an amenable number.

216881889 is a deficient number, since it is larger than the sum of its proper divisors (119506575).

216881889 is a wasteful number, since it uses less digits than its factorization.

216881889 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1475404 (or 1475397 counting only the distinct ones).

The product of its digits is 442368, while the sum is 51.

The square root of 216881889 is about 14726.9103684378. The cubic root of 216881889 is about 600.8154551084.

The spelling of 216881889 in words is "two hundred sixteen million, eight hundred eighty-one thousand, eight hundred eighty-nine".