21121125351516 has 48 divisors (see below), whose sum is σ = 57139276320000. Its totient is φ = 6734271850416.

The previous prime is 21121125351503. The next prime is 21121125351527. The reversal of 21121125351516 is 61515352112112.

21121125351516 is a `hidden beast` number, since 2 + 1 + 1 + 2 + 1 + 125 + 3 + 515 + 16 = 666.

It is a super-2 number, since 2×21121125351516² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4251431766 + ... + 4251436733.

It is an arithmetic number, because the mean of its divisors is an integer number (1190401590000).

Almost surely, 2^{21121125351516} is an apocalyptic number.

It is an amenable number.

21121125351516 is an abundant number, since it is smaller than the sum of its proper divisors (36018150968484).

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

21121125351516 is a wasteful number, since it uses less digits than its factorization.

21121125351516 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8502868535 (or 8502868527 counting only the distinct ones).

The product of its digits is 18000, while the sum is 36.

Adding to 21121125351516 its reverse (61515352112112), we get a palindrome (82636477463628).

The spelling of 21121125351516 in words is "twenty-one trillion, one hundred twenty-one billion, one hundred twenty-five million, three hundred fifty-one thousand, five hundred sixteen".