216442920961 has 4 divisors (see below), whose sum is σ = 216452155972. Its totient is φ = 216433685952.

The previous prime is 216442920949. The next prime is 216442920989. The reversal of 216442920961 is 169029244612.

It is a happy number.

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 115664609025 + 100778311936 = 340095^2 + 317456^2 .

It is a cyclic number.

It is not a de Polignac number, because 216442920961 - 2⁷ = 216442920833 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (216442926961) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4582260 + ... + 4629253.

It is an arithmetic number, because the mean of its divisors is an integer number (54113038993).

Almost surely, 2^216442920961 is an apocalyptic number.

It is an amenable number.

216442920961 is a deficient number, since it is larger than the sum of its proper divisors (9235011).

216442920961 is an equidigital number, since it uses as much as digits as its factorization.

216442920961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9235010.

The product of its (nonzero) digits is 373248, while the sum is 46.

The spelling of 216442920961 in words is "two hundred sixteen billion, four hundred forty-two million, nine hundred twenty thousand, nine hundred sixty-one".