21305300564 has 6 divisors (see below), whose sum is σ = 37284275994. Its totient is φ = 10652650280.

The previous prime is 21305300561. The next prime is 21305300623. The reversal of 21305300564 is 46500350312.

It can be written as a sum of positive squares in only one way, i.e., 12376562500 + 8928738064 = 111250^2 + 94492^2 .

It is a super-3 number, since 3×21305300564³ (a number of 32 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21305300561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2663162567 + ... + 2663162574.

It is an arithmetic number, because the mean of its divisors is an integer number (6214045999).

Almost surely, 2^21305300564 is an apocalyptic number.

It is an amenable number.

21305300564 is a deficient number, since it is larger than the sum of its proper divisors (15978975430).

21305300564 is a wasteful number, since it uses less digits than its factorization.

21305300564 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5326325145 (or 5326325143 counting only the distinct ones).

The product of its (nonzero) digits is 10800, while the sum is 29.

Adding to 21305300564 its reverse (46500350312), we get a palindrome (67805650876).

The spelling of 21305300564 in words is "twenty-one billion, three hundred five million, three hundred thousand, five hundred sixty-four".