16320521777 has 24 divisors (see below), whose sum is σ = 19741847400. Its totient is φ = 13436430336.

The previous prime is 16320521753. The next prime is 16320521783. The reversal of 16320521777 is 77712502361.

It can be written as a sum of positive squares in 4 ways, for example, as 4036081 + 16316485696 = 2009^2 + 127736^2 .

It is not a de Polignac number, because 16320521777 - 2⁸ = 16320521521 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16320523777) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 244499 + ... + 304007.

It is an arithmetic number, because the mean of its divisors is an integer number (822576975).

Almost surely, 2^16320521777 is an apocalyptic number.

It is an amenable number.

16320521777 is a deficient number, since it is larger than the sum of its proper divisors (3421325623).

16320521777 is a wasteful number, since it uses less digits than its factorization.

16320521777 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59745 (or 59738 counting only the distinct ones).

The product of its (nonzero) digits is 123480, while the sum is 41.

The spelling of 16320521777 in words is "sixteen billion, three hundred twenty million, five hundred twenty-one thousand, seven hundred seventy-seven".