8100121666 has 48 divisors (see below), whose sum is σ = 15061538304. Its totient is φ = 3199053312.

The previous prime is 8100121661. The next prime is 8100121697. The reversal of 8100121666 is 6661210018.

It is a super-2 number, since 2×8100121666² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (8100121661) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1589775 + ... + 1594861.

It is an arithmetic number, because the mean of its divisors is an integer number (313782048).

Almost surely, 2^8100121666 is an apocalyptic number.

8100121666 is a deficient number, since it is larger than the sum of its proper divisors (6961416638).

8100121666 is a wasteful number, since it uses less digits than its factorization.

8100121666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5795 (or 5782 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 31.

The square root of 8100121666 is about 90000.6759196841. The cubic root of 8100121666 is about 2008.3089054097.

The spelling of 8100121666 in words is "eight billion, one hundred million, one hundred twenty-one thousand, six hundred sixty-six".