2156073572781 has 6 divisors (see below), whose sum is σ = 3114328494030. Its totient is φ = 1437382381848.

The previous prime is 2156073572771. The next prime is 2156073572789. The reversal of 2156073572781 is 1872753706512.

2156073572781 is a `hidden beast` number, since 2 + 1 + 5 + 60 + 7 + 3 + 572 + 7 + 8 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 1419410132100 + 736663440681 = 1191390^2 + 858291^2 .

It is not a de Polignac number, because 2156073572781 - 2¹⁸ = 2156073310637 is a prime.

It is a super-2 number, since 2×2156073572781² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2156073572789) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 119781865146 + ... + 119781865163.

It is an arithmetic number, because the mean of its divisors is an integer number (519054749005).

Almost surely, 2^{2156073572781} is an apocalyptic number.

It is an amenable number.

2156073572781 is a deficient number, since it is larger than the sum of its proper divisors (958254921249).

2156073572781 is a wasteful number, since it uses less digits than its factorization.

2156073572781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 239563730315 (or 239563730312 counting only the distinct ones).

The product of its (nonzero) digits is 4939200, while the sum is 54.

The spelling of 2156073572781 in words is "two trillion, one hundred fifty-six billion, seventy-three million, five hundred seventy-two thousand, seven hundred eighty-one".