216461246509 has 4 divisors (see below), whose sum is σ = 217657165180. Its totient is φ = 215265327840.

The previous prime is 216461246501. The next prime is 216461246527. The reversal of 216461246509 is 905642164612.

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

It can be written as a sum of positive squares in 2 ways, for example, as 97108270884 + 119352975625 = 311622^2 + 345475^2 .

It is a cyclic number.

It is not a de Polignac number, because 216461246509 - 2³ = 216461246501 is a prime.

It is a super-4 number, since 4×216461246509⁴ (a number of 46 digits) contains 4444 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 (216461246501) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 597959064 + ... + 597959425.

It is an arithmetic number, because the mean of its divisors is an integer number (54414291295).

Almost surely, 2^216461246509 is an apocalyptic number.

It is an amenable number.

216461246509 is a deficient number, since it is larger than the sum of its proper divisors (1195918671).

216461246509 is a wasteful number, since it uses less digits than its factorization.

216461246509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1195918670.

The product of its (nonzero) digits is 622080, while the sum is 46.

The spelling of 216461246509 in words is "two hundred sixteen billion, four hundred sixty-one million, two hundred forty-six thousand, five hundred nine".