16195722920881 has 9 divisors (see below), whose sum is σ = 18839955351531. Its totient is φ = 13882024071552.

The previous prime is 16195722920869. The next prime is 16195722920929. The reversal of 16195722920881 is 18802922759161.

The square root of 16195722920881 is 4024391.

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., 15152840802225 + 1042882118656 = 3892665^2 + 1021216^2 .

It is not a de Polignac number, because 16195722920881 - 2²³ = 16195714532273 is a prime.

It is a super-2 number, since 2×16195722920881² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16195722920681) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 27883281 + ... + 28458193.

Almost surely, 2^{16195722920881} is an apocalyptic number.

16195722920881 is the 4024391-st square number.

16195722920881 is the 2012196-th centered octagonal number.

It is an amenable number.

16195722920881 is a deficient number, since it is larger than the sum of its proper divisors (2644232430650).

16195722920881 is an frugal number, since it uses more digits than its factorization.

16195722920881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1149840 (or 574920 counting only the distinct ones).

The product of its (nonzero) digits is 8709120, while the sum is 61.

It can be divided in two parts, 1619 and 5722920881, that added together give a square (5722922500 = 75650²).

The spelling of 16195722920881 in words is "sixteen trillion, one hundred ninety-five billion, seven hundred twenty-two million, nine hundred twenty thousand, eight hundred eighty-one".