216312451621 has 16 divisors (see below), whose sum is σ = 255452608000. Its totient is φ = 183063679344.

The previous prime is 216312451609. The next prime is 216312451631. The reversal of 216312451621 is 126154213612.

It is not a de Polignac number, because 216312451621 - 2¹³ = 216312443429 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216312451631) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3964350 + ... + 4018543.

It is an arithmetic number, because the mean of its divisors is an integer number (15965788000).

Almost surely, 2^216312451621 is an apocalyptic number.

It is an amenable number.

216312451621 is a deficient number, since it is larger than the sum of its proper divisors (39140156379).

216312451621 is an frugal number, since it uses more digits than its factorization.

216312451621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7982993 (or 7982979 counting only the distinct ones).

The product of its digits is 17280, while the sum is 34.

The spelling of 216312451621 in words is "two hundred sixteen billion, three hundred twelve million, four hundred fifty-one thousand, six hundred twenty-one".