21115323151987 has 12 divisors (see below), whose sum is σ = 22357737322536. Its totient is φ = 19938830672160.

The previous prime is 21115323151919. The next prime is 21115323151991. The reversal of 21115323151987 is 78915132351112.

It is not a de Polignac number, because 21115323151987 - 2³⁵ = 21080963413619 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21115323151987.

It is not an unprimeable number, because it can be changed into a prime (21115323151187) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 95151714 + ... + 95373367.

It is an arithmetic number, because the mean of its divisors is an integer number (1863144776878).

Almost surely, 2^{21115323151987} is an apocalyptic number.

21115323151987 is a deficient number, since it is larger than the sum of its proper divisors (1242414170549).

21115323151987 is a wasteful number, since it uses less digits than its factorization.

21115323151987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 190525426 (or 190525407 counting only the distinct ones).

The product of its digits is 453600, while the sum is 49.

The spelling of 21115323151987 in words is "twenty-one trillion, one hundred fifteen billion, three hundred twenty-three million, one hundred fifty-one thousand, nine hundred eighty-seven".