16721531346 has 144 divisors (see below), whose sum is σ = 39025361088. Its totient is φ = 4739232960.

The previous prime is 16721531293. The next prime is 16721531413. The reversal of 16721531346 is 64313512761.

It is a super-2 number, since 2×16721531346² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 235514491 + ... + 235514561.

It is an arithmetic number, because the mean of its divisors is an integer number (271009452).

Almost surely, 2^16721531346 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 16721531346, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (19512680544).

16721531346 is an abundant number, since it is smaller than the sum of its proper divisors (22303829742).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

16721531346 is a wasteful number, since it uses less digits than its factorization.

16721531346 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 269 (or 155 counting only the distinct ones).

The product of its digits is 90720, while the sum is 39.

The spelling of 16721531346 in words is "sixteen billion, seven hundred twenty-one million, five hundred thirty-one thousand, three hundred forty-six".