21115363500646 has 16 divisors (see below), whose sum is σ = 31710575243088. Its totient is φ = 10545175123200.

The previous prime is 21115363500617. The next prime is 21115363500661. The reversal of 21115363500646 is 64600536351112.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11747266 + ... + 13424938.

It is an arithmetic number, because the mean of its divisors is an integer number (1981910952693).

Almost surely, 2^{21115363500646} is an apocalyptic number.

21115363500646 is a deficient number, since it is larger than the sum of its proper divisors (10595211742442).

21115363500646 is a wasteful number, since it uses less digits than its factorization.

21115363500646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1685127.

The product of its (nonzero) digits is 388800, while the sum is 43.

Adding to 21115363500646 its reverse (64600536351112), we get a palindrome (85715899851758).

The spelling of 21115363500646 in words is "twenty-one trillion, one hundred fifteen billion, three hundred sixty-three million, five hundred thousand, six hundred forty-six".