21503143305 has 80 divisors (see below), whose sum is σ = 44884502784. Its totient is φ = 9644469120.

The previous prime is 21503143247. The next prime is 21503143327. The reversal of 21503143305 is 50334130512.

21503143305 is a `hidden beast` number, since 2 + 15 + 0 + 314 + 330 + 5 = 666.

It is not a de Polignac number, because 21503143305 - 2⁶ = 21503143241 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 78700 + ... + 221810.

Almost surely, 2^21503143305 is an apocalyptic number.

It is an amenable number.

21503143305 is an abundant number, since it is smaller than the sum of its proper divisors (23381359479).

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

21503143305 is a wasteful number, since it uses less digits than its factorization.

21503143305 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 143188 (or 143179 counting only the distinct ones).

The product of its (nonzero) digits is 5400, while the sum is 27.

Adding to 21503143305 its reverse (50334130512), we get a palindrome (71837273817).

The spelling of 21503143305 in words is "twenty-one billion, five hundred three million, one hundred forty-three thousand, three hundred five".