16545766613421 has 16 divisors (see below), whose sum is σ = 23222225945600. Its totient is φ = 10449914046768.

The previous prime is 16545766613417. The next prime is 16545766613423. The reversal of 16545766613421 is 12431666754561.

It is a happy number.

It is not a de Polignac number, because 16545766613421 - 2² = 16545766613417 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (57).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16545766613423) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18115020 + ... + 19006458.

It is an arithmetic number, because the mean of its divisors is an integer number (1451389121600).

Almost surely, 2^{16545766613421} is an apocalyptic number.

It is an amenable number.

16545766613421 is a deficient number, since it is larger than the sum of its proper divisors (6676459332179).

16545766613421 is a wasteful number, since it uses less digits than its factorization.

16545766613421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1217088.

The product of its digits is 21772800, while the sum is 57.

The spelling of 16545766613421 in words is "sixteen trillion, five hundred forty-five billion, seven hundred sixty-six million, six hundred thirteen thousand, four hundred twenty-one".