2166166520651 has 32 divisors (see below), whose sum is σ = 2516540755968. Its totient is φ = 1826323107840.

The previous prime is 2166166520641. The next prime is 2166166520711. The reversal of 2166166520651 is 1560256616612.

It is not a de Polignac number, because 2166166520651 - 2¹⁸ = 2166166258507 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2166166520596 and 2166166520605.

It is not an unprimeable number, because it can be changed into a prime (2166166520621) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 58897670 + ... + 58934436.

It is an arithmetic number, because the mean of its divisors is an integer number (78641898624).

Almost surely, 2^{2166166520651} is an apocalyptic number.

2166166520651 is a deficient number, since it is larger than the sum of its proper divisors (350374235317).

2166166520651 is a wasteful number, since it uses less digits than its factorization.

2166166520651 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37451.

The product of its (nonzero) digits is 777600, while the sum is 47.

The spelling of 2166166520651 in words is "two trillion, one hundred sixty-six billion, one hundred sixty-six million, five hundred twenty thousand, six hundred fifty-one".