21085646315 has 8 divisors (see below), whose sum is σ = 25360415520. Its totient is φ = 16830090432.

The previous prime is 21085646311. The next prime is 21085646333. The reversal of 21085646315 is 51364658012.

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

It is a cyclic number.

It is not a de Polignac number, because 21085646315 - 2² = 21085646311 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21085646311) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4800914 + ... + 4805303.

It is an arithmetic number, because the mean of its divisors is an integer number (3170051940).

Almost surely, 2^21085646315 is an apocalyptic number.

21085646315 is a deficient number, since it is larger than the sum of its proper divisors (4274769205).

21085646315 is an equidigital number, since it uses as much as digits as its factorization.

21085646315 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9606661.

The product of its (nonzero) digits is 172800, while the sum is 41.

The spelling of 21085646315 in words is "twenty-one billion, eighty-five million, six hundred forty-six thousand, three hundred fifteen".