21534489812 has 12 divisors (see below), whose sum is σ = 41111298816. Its totient is φ = 9788404440.

The previous prime is 21534489797. The next prime is 21534489859. The reversal of 21534489812 is 21898443512.

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, 244710068 + ... + 244710155.

It is an arithmetic number, because the mean of its divisors is an integer number (3425941568).

Almost surely, 2^21534489812 is an apocalyptic number.

21534489812 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21534489812 is a deficient number, since it is larger than the sum of its proper divisors (19576809004).

21534489812 is a wasteful number, since it uses less digits than its factorization.

21534489812 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 489420238 (or 489420236 counting only the distinct ones).

The product of its digits is 552960, while the sum is 47.

The spelling of 21534489812 in words is "twenty-one billion, five hundred thirty-four million, four hundred eighty-nine thousand, eight hundred twelve".