21201110102178 has 12 divisors (see below), whose sum is σ = 45935738554758. Its totient is φ = 7067036700720.

The previous prime is 21201110102177. The next prime is 21201110102191. The reversal of 21201110102178 is 87120101110212.

It can be written as a sum of positive squares in only one way, i.e., 12990495518289 + 8210614583889 = 3604233^2 + 2865417^2 .

It is not an unprimeable number, because it can be changed into a prime (21201110102177) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 588919725043 + ... + 588919725078.

Almost surely, 2^{21201110102178} is an apocalyptic number.

21201110102178 is an abundant number, since it is smaller than the sum of its proper divisors (24734628452580).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21201110102178 is a wasteful number, since it uses less digits than its factorization.

21201110102178 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1177839450129 (or 1177839450126 counting only the distinct ones).

The product of its (nonzero) digits is 448, while the sum is 27.

The spelling of 21201110102178 in words is "twenty-one trillion, two hundred one billion, one hundred ten million, one hundred two thousand, one hundred seventy-eight".