4020991468081 has 27 divisors (see below), whose sum is σ = 4936947479019. Its totient is φ = 3264949438128.

The previous prime is 4020991468063. The next prime is 4020991468121. The reversal of 4020991468081 is 1808641990204.

The square root of 4020991468081 is 2005241.

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., 119118168225 + 3901873299856 = 345135^2 + 1975316^2 .

It is not a de Polignac number, because 4020991468081 - 2²⁹ = 4020454597169 is a prime.

It is a super-2 number, since 2×4020991468081² (a number of 26 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (4020991468031) 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, 266689515 + ... + 266704591.

Almost surely, 2^{4020991468081} is an apocalyptic number.

4020991468081 is the 2005241-st square number.

4020991468081 is the 1002621-st centered octagonal number.

It is an amenable number.

4020991468081 is a deficient number, since it is larger than the sum of its proper divisors (915956010938).

4020991468081 is an frugal number, since it uses more digits than its factorization.

4020991468081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30206 (or 15103 counting only the distinct ones).

The product of its (nonzero) digits is 995328, while the sum is 52.

The spelling of 4020991468081 in words is "four trillion, twenty billion, nine hundred ninety-one million, four hundred sixty-eight thousand, eighty-one".