216019881 has 36 divisors (see below), whose sum is σ = 395978544. Its totient is φ = 112215600.

The previous prime is 216019879. The next prime is 216019883. The reversal of 216019881 is 188910612.

It is an interprime number because it is at equal distance from previous prime (216019879) and next prime (216019883).

It is not a de Polignac number, because 216019881 - 2¹ = 216019879 is a prime.

It is a super-2 number, since 2×216019881² = 93329177974508322, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (216019883) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 17415 + ... + 27116.

It is an arithmetic number, because the mean of its divisors is an integer number (10999404).

Almost surely, 2^216019881 is an apocalyptic number.

216019881 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

216019881 is a deficient number, since it is larger than the sum of its proper divisors (179958663).

216019881 is a wasteful number, since it uses less digits than its factorization.

216019881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44562 (or 44552 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 36.

The square root of 216019881 is about 14697.6148064916. The cubic root of 216019881 is about 600.0184077686.

The spelling of 216019881 in words is "two hundred sixteen million, nineteen thousand, eight hundred eighty-one".