21041243136 has 99 divisors (see below), whose sum is σ = 60796368763. Its totient is φ = 7009105920.

The previous prime is 21041243129. The next prime is 21041243233. The reversal of 21041243136 is 63134214012.

It is a happy number.

The square root of 21041243136 is 145056.

It is a perfect power (a square), and thus also a powerful number.

21041243136 is a `hidden beast` number, since 210 + 4 + 12 + 431 + 3 + 6 = 666.

It is a super-2 number, since 2×21041243136² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 13924621 + ... + 13926131.

Almost surely, 2^21041243136 is an apocalyptic number.

21041243136 is the 145056-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21041243136

21041243136 is an abundant number, since it is smaller than the sum of its proper divisors (39755125627).

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

21041243136 is an frugal number, since it uses more digits than its factorization.

21041243136 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3048 (or 1516 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 27.

Adding to 21041243136 its reverse (63134214012), we get a palindrome (84175457148).

The spelling of 21041243136 in words is "twenty-one billion, forty-one million, two hundred forty-three thousand, one hundred thirty-six".