2157666860081 has 16 divisors (see below), whose sum is σ = 2171065438080. Its totient is φ = 2144314567680.

The previous prime is 2157666860077. The next prime is 2157666860101. The reversal of 2157666860081 is 1800686667512.

It is a cyclic number.

It is not a de Polignac number, because 2157666860081 - 2² = 2157666860077 is a prime.

It is a super-2 number, since 2×2157666860081² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2157666859999 and 2157666860026.

It is not an unprimeable number, because it can be changed into a prime (2157666860071) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 396554321 + ... + 396559761.

It is an arithmetic number, because the mean of its divisors is an integer number (135691589880).

Almost surely, 2^{2157666860081} is an apocalyptic number.

It is an amenable number.

2157666860081 is a deficient number, since it is larger than the sum of its proper divisors (13398577999).

2157666860081 is a wasteful number, since it uses less digits than its factorization.

2157666860081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9256.

The product of its (nonzero) digits is 5806080, while the sum is 56.

The spelling of 2157666860081 in words is "two trillion, one hundred fifty-seven billion, six hundred sixty-six million, eight hundred sixty thousand, eighty-one".