21302656505 has 8 divisors (see below), whose sum is σ = 27529586952. Its totient is φ = 15731192448.

The previous prime is 21302656451. The next prime is 21302656513. The reversal of 21302656505 is 50565620312.

It can be written as a sum of positive squares in 4 ways, for example, as 1940490601 + 19362165904 = 44051^2 + 139148^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21302656505 is a prime.

It is a Duffinian 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, 163866524 + ... + 163866653.

It is an arithmetic number, because the mean of its divisors is an integer number (3441198369).

Almost surely, 2^21302656505 is an apocalyptic number.

It is an amenable number.

21302656505 is a deficient number, since it is larger than the sum of its proper divisors (6226930447).

21302656505 is a wasteful number, since it uses less digits than its factorization.

21302656505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 327733195.

The product of its (nonzero) digits is 54000, while the sum is 35.

The spelling of 21302656505 in words is "twenty-one billion, three hundred two million, six hundred fifty-six thousand, five hundred five".