21515423134012 has 12 divisors (see below), whose sum is σ = 37939410260136. Its totient is φ = 10675591631120.

The previous prime is 21515423133929. The next prime is 21515423134021. The reversal of 21515423134012 is 21043132451512.

It is a super-2 number, since 2×21515423134012² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20529983383 + ... + 20529984430.

It is an arithmetic number, because the mean of its divisors is an integer number (3161617521678).

Almost surely, 2^{21515423134012} is an apocalyptic number.

It is an amenable number.

21515423134012 is a deficient number, since it is larger than the sum of its proper divisors (16423987126124).

21515423134012 is a wasteful number, since it uses less digits than its factorization.

21515423134012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41059967948 (or 41059967946 counting only the distinct ones).

The product of its (nonzero) digits is 28800, while the sum is 34.

Adding to 21515423134012 its reverse (21043132451512), we get a palindrome (42558555585524).

The spelling of 21515423134012 in words is "twenty-one trillion, five hundred fifteen billion, four hundred twenty-three million, one hundred thirty-four thousand, twelve".