21213560223144 has 80 divisors (see below), whose sum is σ = 59469235499520. Its totient is φ = 7065042976800.

The previous prime is 21213560223143. The next prime is 21213560223181. The reversal of 21213560223144 is 44132206531212.

It is a happy number.

21213560223144 is a `hidden beast` number, since 2 + 1 + 2 + 1 + 3 + 5 + 602 + 2 + 3 + 1 + 44 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 21213560223099 and 21213560223108.

It is not an unprimeable number, because it can be changed into a prime (21213560223143) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 13475254 + ... + 14966949.

It is an arithmetic number, because the mean of its divisors is an integer number (743365443744).

Almost surely, 2^{21213560223144} is an apocalyptic number.

21213560223144 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21213560223144 is an abundant number, since it is smaller than the sum of its proper divisors (38255675276376).

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

21213560223144 is a wasteful number, since it uses less digits than its factorization.

21213560223144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28443372 (or 28443359 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 36.

Adding to 21213560223144 its reverse (44132206531212), we get a palindrome (65345766754356).

The spelling of 21213560223144 in words is "twenty-one trillion, two hundred thirteen billion, five hundred sixty million, two hundred twenty-three thousand, one hundred forty-four".