216309487 has 2 divisors, whose sum is σ = 216309488. Its totient is φ = 216309486.

The previous prime is 216309473. The next prime is 216309497. The reversal of 216309487 is 784903612.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-216309487 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (216309407) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108154743 + 108154744.

It is an arithmetic number, because the mean of its divisors is an integer number (108154744).

Almost surely, 2^216309487 is an apocalyptic number.

216309487 is a deficient number, since it is larger than the sum of its proper divisors (1).

216309487 is an equidigital number, since it uses as much as digits as its factorization.

216309487 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 72576, while the sum is 40.

The square root of 216309487 is about 14707.4636494536. The cubic root of 216309487 is about 600.2864252829.

The spelling of 216309487 in words is "two hundred sixteen million, three hundred nine thousand, four hundred eighty-seven".