216510071 has 4 divisors (see below), whose sum is σ = 216579000. Its totient is φ = 216441144.

The previous prime is 216510013. The next prime is 216510083. The reversal of 216510071 is 170015612.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-216510071 is a prime.

It is a super-2 number, since 2×216510071² = 93753221688850082, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216510001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 29516 + ... + 36113.

It is an arithmetic number, because the mean of its divisors is an integer number (54144750).

Almost surely, 2^216510071 is an apocalyptic number.

216510071 is a deficient number, since it is larger than the sum of its proper divisors (68929).

216510071 is an equidigital number, since it uses as much as digits as its factorization.

216510071 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68928.

The product of its (nonzero) digits is 420, while the sum is 23.

The square root of 216510071 is about 14714.2811920936. The cubic root of 216510071 is about 600.4719166900.

Adding to 216510071 its reverse (170015612), we get a palindrome (386525683).

The spelling of 216510071 in words is "two hundred sixteen million, five hundred ten thousand, seventy-one".