21678182715 has 64 divisors (see below), whose sum is σ = 41755852800. Its totient is φ = 9381826944.

The previous prime is 21678182693. The next prime is 21678182717. The reversal of 21678182715 is 51728187612.

It is not a de Polignac number, because 21678182715 - 2⁶ = 21678182651 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21678182717) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 3745714 + ... + 3751496.

It is an arithmetic number, because the mean of its divisors is an integer number (652435200).

Almost surely, 2^21678182715 is an apocalyptic number.

21678182715 is a deficient number, since it is larger than the sum of its proper divisors (20077670085).

21678182715 is a wasteful number, since it uses less digits than its factorization.

21678182715 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7696.

The product of its digits is 376320, while the sum is 48.

The spelling of 21678182715 in words is "twenty-one billion, six hundred seventy-eight million, one hundred eighty-two thousand, seven hundred fifteen".