16509756768400 has 135 divisors (see below), whose sum is σ = 46142148342681. Its totient is φ = 5660293000320.

The previous prime is 16509756768347. The next prime is 16509756768409. The reversal of 16509756768400 is 486765790561.

The square root of 16509756768400 is 4063220.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 5943512436624 + 10566244331776 = 2437932^2 + 3250576^2 .

It is a super-2 number, since 2×16509756768400² (a number of 27 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (64) coincides with the sum of the digits of its prime factors.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16509756768409) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 568836289 + ... + 568865311.

Almost surely, 2^{16509756768400} is an apocalyptic number.

16509756768400 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

16509756768400 is the 4063220-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 16509756768400

16509756768400 is an abundant number, since it is smaller than the sum of its proper divisors (29632391574281).

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

16509756768400 is an frugal number, since it uses more digits than its factorization.

16509756768400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58078 (or 29037 counting only the distinct ones).

The product of its (nonzero) digits is 76204800, while the sum is 64.

The spelling of 16509756768400 in words is "sixteen trillion, five hundred nine billion, seven hundred fifty-six million, seven hundred sixty-eight thousand, four hundred".