1971132613081 has 4 divisors (see below), whose sum is σ = 1971135677412. Its totient is φ = 1971129548752.

The previous prime is 1971132613033. The next prime is 1971132613123. The reversal of 1971132613081 is 1803162311791.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1430856161856 + 540276451225 = 1196184^2 + 735035^2 .

It is a cyclic number.

It is not a de Polignac number, because 1971132613081 - 2²³ = 1971124224473 is a prime.

It is a super-2 number, since 2×1971132613081² (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 (1971132610081) 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, 154186 + ... + 1991491.

It is an arithmetic number, because the mean of its divisors is an integer number (492783919353).

Almost surely, 2^{1971132613081} is an apocalyptic number.

It is an amenable number.

1971132613081 is a deficient number, since it is larger than the sum of its proper divisors (3064331).

1971132613081 is an equidigital number, since it uses as much as digits as its factorization.

1971132613081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3064330.

The product of its (nonzero) digits is 54432, while the sum is 43.

The spelling of 1971132613081 in words is "one trillion, nine hundred seventy-one billion, one hundred thirty-two million, six hundred thirteen thousand, eighty-one".