2156456666 has 16 divisors (see below), whose sum is σ = 3981151104. Its totient is φ = 853103664.

The previous prime is 2156456657. The next prime is 2156456669. The reversal of 2156456666 is 6666546512.

It is a self number, because there is not a number n which added to its sum of digits gives 2156456666.

It is not an unprimeable number, because it can be changed into a prime (2156456669) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5924150 + ... + 5924513.

It is an arithmetic number, because the mean of its divisors is an integer number (248821944).

Almost surely, 2^2156456666 is an apocalyptic number.

2156456666 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

2156456666 is a deficient number, since it is larger than the sum of its proper divisors (1824694438).

2156456666 is a wasteful number, since it uses less digits than its factorization.

2156456666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11848685.

The product of its digits is 1555200, while the sum is 47.

The square root of 2156456666 is about 46437.6643038816. The cubic root of 2156456666 is about 1291.9535862612.

The spelling of 2156456666 in words is "two billion, one hundred fifty-six million, four hundred fifty-six thousand, six hundred sixty-six".