2195556391081 has 9 divisors (see below), whose sum is σ = 2212639920669. Its totient is φ = 2178603792300.

The previous prime is 2195556391057. The next prime is 2195556391087. The reversal of 2195556391081 is 1801936555912.

The square root of 2195556391081 is 1481741.

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

It is not a de Polignac number, because 2195556391081 - 2¹³ = 2195556382889 is a prime.

It is a super-2 number, since 2×2195556391081² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2195556391087) 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, 194102416 + ... + 194113726.

Almost surely, 2^{2195556391081} is an apocalyptic number.

2195556391081 is the 1481741-st square number.

2195556391081 is the 740871-st centered octagonal number.

It is an amenable number.

2195556391081 is a deficient number, since it is larger than the sum of its proper divisors (17083529588).

2195556391081 is an frugal number, since it uses more digits than its factorization.

2195556391081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22884 (or 11442 counting only the distinct ones).

The product of its (nonzero) digits is 2916000, while the sum is 55.

The spelling of 2195556391081 in words is "two trillion, one hundred ninety-five billion, five hundred fifty-six million, three hundred ninety-one thousand, eighty-one".