21603636202164 has 12 divisors (see below), whose sum is σ = 50408484471744. Its totient is φ = 7201212067384.

The previous prime is 21603636202153. The next prime is 21603636202201. The reversal of 21603636202164 is 46120263630612.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (12).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 900151508412 + ... + 900151508435.

It is an arithmetic number, because the mean of its divisors is an integer number (4200707039312).

Almost surely, 2^{21603636202164} is an apocalyptic number.

It is an amenable number.

21603636202164 is an abundant number, since it is smaller than the sum of its proper divisors (28804848269580).

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

21603636202164 is a wasteful number, since it uses less digits than its factorization.

21603636202164 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1800303016854 (or 1800303016852 counting only the distinct ones).

The product of its (nonzero) digits is 373248, while the sum is 42.

Adding to 21603636202164 its reverse (46120263630612), we get a palindrome (67723899832776).

The spelling of 21603636202164 in words is "twenty-one trillion, six hundred three billion, six hundred thirty-six million, two hundred two thousand, one hundred sixty-four".