21305123521104 has 40 divisors (see below), whose sum is σ = 55434194310880. Its totient is φ = 7050616414848.

The previous prime is 21305123521081. The next prime is 21305123521111. The reversal of 21305123521104 is 40112532150312.

It is a happy number.

It is a congruent number.

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, 1596600307 + ... + 1596613650.

It is an arithmetic number, because the mean of its divisors is an integer number (1385854857772).

Almost surely, 2^{21305123521104} is an apocalyptic number.

21305123521104 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21305123521104 is an abundant number, since it is smaller than the sum of its proper divisors (34129070789776).

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

21305123521104 is a wasteful number, since it uses less digits than its factorization.

21305123521104 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3193214107 (or 3193214101 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 30.

Adding to 21305123521104 its reverse (40112532150312), we get a palindrome (61417655671416).

The spelling of 21305123521104 in words is "twenty-one trillion, three hundred five billion, one hundred twenty-three million, five hundred twenty-one thousand, one hundred four".