216461987 has 8 divisors (see below), whose sum is σ = 247680000. Its totient is φ = 185317704.

The previous prime is 216461953. The next prime is 216462007. The reversal of 216461987 is 789164612.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 216461987 - 2²⁰ = 215413411 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (216461087) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11987 + ... + 24012.

It is an arithmetic number, because the mean of its divisors is an integer number (30960000).

Almost surely, 2^216461987 is an apocalyptic number.

216461987 is a deficient number, since it is larger than the sum of its proper divisors (31218013).

216461987 is an equidigital number, since it uses as much as digits as its factorization.

216461987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36865.

The product of its digits is 145152, while the sum is 44.

The square root of 216461987 is about 14712.6471785332. The cubic root of 216461987 is about 600.4274611301.

The spelling of 216461987 in words is "two hundred sixteen million, four hundred sixty-one thousand, nine hundred eighty-seven".