21115351512 has 80 divisors (see below), whose sum is σ = 60741051360. Its totient is φ = 6848214336.

The previous prime is 21115351487. The next prime is 21115351513. The reversal of 21115351512 is 21515351112.

It is a happy number.

21115351512 is a `hidden beast` number, since 2 + 1 + 115 + 35 + 1 + 512 = 666.

It is a super-2 number, since 2×21115351512² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21115351513) 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 19 ways as a sum of consecutive naturals, for example, 416368 + ... + 464319.

It is an arithmetic number, because the mean of its divisors is an integer number (759263142).

Almost surely, 2^21115351512 is an apocalyptic number.

It is an amenable number.

21115351512 is an abundant number, since it is smaller than the sum of its proper divisors (39625699848).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21115351512 is a wasteful number, since it uses less digits than its factorization.

21115351512 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 880742 (or 880729 counting only the distinct ones).

The product of its digits is 1500, while the sum is 27.

The spelling of 21115351512 in words is "twenty-one billion, one hundred fifteen million, three hundred fifty-one thousand, five hundred twelve".