21081170615 has 16 divisors (see below), whose sum is σ = 26072703360. Its totient is φ = 16354656000.

The previous prime is 21081170599. The next prime is 21081170647. The reversal of 21081170615 is 51607118012.

It is not a de Polignac number, because 21081170615 - 2⁴ = 21081170599 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 385886 + ... + 437115.

It is an arithmetic number, because the mean of its divisors is an integer number (1629543960).

Almost surely, 2^21081170615 is an apocalyptic number.

21081170615 is a deficient number, since it is larger than the sum of its proper divisors (4991532745).

21081170615 is a wasteful number, since it uses less digits than its factorization.

21081170615 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 823162.

The product of its (nonzero) digits is 3360, while the sum is 32.

Adding to 21081170615 its reverse (51607118012), we get a palindrome (72688288627).

The spelling of 21081170615 in words is "twenty-one billion, eighty-one million, one hundred seventy thousand, six hundred fifteen".