16800821731 has 4 divisors (see below), whose sum is σ = 17254898032. Its totient is φ = 16346745432.

The previous prime is 16800821701. The next prime is 16800821759. The reversal of 16800821731 is 13712800861.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13712800861 = 3701 ⋅3705161.

It is a cyclic number.

It is not a de Polignac number, because 16800821731 - 2⁷ = 16800821603 is a prime.

It is a super-2 number, since 2×16800821731² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (37), and also a Moran number because the ratio is a prime number: 454076263 = 16800821731 / (1 + 6 + 8 + 0 + 0 + 8 + 2 + 1 + 7 + 3 + 1).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16800821701) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 227038095 + ... + 227038168.

It is an arithmetic number, because the mean of its divisors is an integer number (4313724508).

Almost surely, 2^16800821731 is an apocalyptic number.

16800821731 is a deficient number, since it is larger than the sum of its proper divisors (454076301).

16800821731 is an equidigital number, since it uses as much as digits as its factorization.

16800821731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 454076300.

The product of its (nonzero) digits is 16128, while the sum is 37.

The spelling of 16800821731 in words is "sixteen billion, eight hundred million, eight hundred twenty-one thousand, seven hundred thirty-one".