21530535051340 has 24 divisors (see below), whose sum is σ = 51673284123552. Its totient is φ = 7381897731840.

The previous prime is 21530535051301. The next prime is 21530535051383. The reversal of 21530535051340 is 4315053503512.

It is a self number, because there is not a number n which added to its sum of digits gives 21530535051340.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 76894767901 + ... + 76894768180.

It is an arithmetic number, because the mean of its divisors is an integer number (2153053505148).

Almost surely, 2^{21530535051340} is an apocalyptic number.

21530535051340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21530535051340 is an abundant number, since it is smaller than the sum of its proper divisors (30142749072212).

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

21530535051340 is a wasteful number, since it uses less digits than its factorization.

21530535051340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 153789536097 (or 153789536095 counting only the distinct ones).

The product of its (nonzero) digits is 135000, while the sum is 37.

Adding to 21530535051340 its reverse (4315053503512), we get a palindrome (25845588554852).

The spelling of 21530535051340 in words is "twenty-one trillion, five hundred thirty billion, five hundred thirty-five million, fifty-one thousand, three hundred forty".