21305134052 has 6 divisors (see below), whose sum is σ = 37283984598. Its totient is φ = 10652567024.

The previous prime is 21305134027. The next prime is 21305134057. The reversal of 21305134052 is 25043150312.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 19094817856 + 2210316196 = 138184^2 + 47014^2 .

It is not an unprimeable number, because it can be changed into a prime (21305134057) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2663141753 + ... + 2663141760.

It is an arithmetic number, because the mean of its divisors is an integer number (6213997433).

Almost surely, 2^21305134052 is an apocalyptic number.

It is an amenable number.

21305134052 is a deficient number, since it is larger than the sum of its proper divisors (15978850546).

21305134052 is a wasteful number, since it uses less digits than its factorization.

21305134052 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5326283517 (or 5326283515 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 26.

Adding to 21305134052 its reverse (25043150312), we get a palindrome (46348284364).

The spelling of 21305134052 in words is "twenty-one billion, three hundred five million, one hundred thirty-four thousand, fifty-two".