21505142323512 has 24 divisors (see below), whose sum is σ = 58243093793040. Its totient is φ = 7168380774480.

The previous prime is 21505142323501. The next prime is 21505142323583. The reversal of 21505142323512 is 21532324150512.

21505142323512 is a `hidden beast` number, since 2 + 1 + 50 + 51 + 4 + 23 + 23 + 512 = 666.

It is a tau number, because it is divible by the number of its divisors (24).

It is a super-2 number, since 2×21505142323512² (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 polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 149341266064 + ... + 149341266207.

It is an arithmetic number, because the mean of its divisors is an integer number (2426795574710).

Almost surely, 2^{21505142323512} is an apocalyptic number.

It is an amenable number.

21505142323512 is an abundant number, since it is smaller than the sum of its proper divisors (36737951469528).

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

21505142323512 is a wasteful number, since it uses less digits than its factorization.

21505142323512 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 298682532283 (or 298682532276 counting only the distinct ones).

The product of its (nonzero) digits is 72000, while the sum is 36.

The spelling of 21505142323512 in words is "twenty-one trillion, five hundred five billion, one hundred forty-two million, three hundred twenty-three thousand, five hundred twelve".