21503764121166 has 24 divisors (see below), whose sum is σ = 46592480829960. Its totient is φ = 7167768773616.

The previous prime is 21503764121159. The next prime is 21503764121201. The reversal of 21503764121166 is 66112146730512.

It is a happy number.

21503764121166 is a `hidden beast` number, since 2 + 1 + 5 + 0 + 3 + 76 + 412 + 1 + 166 = 666.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11846085 + ... + 13540208.

It is an arithmetic number, because the mean of its divisors is an integer number (1941353367915).

Almost surely, 2^{21503764121166} is an apocalyptic number.

21503764121166 is an abundant number, since it is smaller than the sum of its proper divisors (25088716708794).

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

21503764121166 is a wasteful number, since it uses less digits than its factorization.

21503764121166 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25433360 (or 25433357 counting only the distinct ones).

The product of its (nonzero) digits is 362880, while the sum is 45.

The spelling of 21503764121166 in words is "twenty-one trillion, five hundred three billion, seven hundred sixty-four million, one hundred twenty-one thousand, one hundred sixty-six".