16312266721 has 4 divisors (see below), whose sum is σ = 16313260032. Its totient is φ = 16311273412.

The previous prime is 16312266679. The next prime is 16312266791. The reversal of 16312266721 is 12766221361.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 12766221361 = 1549 ⋅8241589.

It is a cyclic number.

It is not a de Polignac number, because 16312266721 - 2¹⁵ = 16312233953 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16312266791) 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, 471601 + ... + 505006.

It is an arithmetic number, because the mean of its divisors is an integer number (4078315008).

Almost surely, 2^16312266721 is an apocalyptic number.

It is an amenable number.

16312266721 is a deficient number, since it is larger than the sum of its proper divisors (993311).

16312266721 is an equidigital number, since it uses as much as digits as its factorization.

16312266721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 993310.

The product of its digits is 36288, while the sum is 37.

The spelling of 16312266721 in words is "sixteen billion, three hundred twelve million, two hundred sixty-six thousand, seven hundred twenty-one".