21214251455136 has 96 divisors (see below), whose sum is σ = 56602772545536. Its totient is φ = 6955642848000.

The previous prime is 21214251455107. The next prime is 21214251455143. The reversal of 21214251455136 is 63155415241212.

It is a tau number, because it is divible by the number of its divisors (96).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 673000 + ... + 6548391.

It is an arithmetic number, because the mean of its divisors is an integer number (589612214016).

Almost surely, 2^{21214251455136} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21214251455136, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28301386272768).

21214251455136 is an abundant number, since it is smaller than the sum of its proper divisors (35388521090400).

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

21214251455136 is a wasteful number, since it uses less digits than its factorization.

21214251455136 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7221906 (or 7221898 counting only the distinct ones).

The product of its digits is 288000, while the sum is 42.

Adding to 21214251455136 its reverse (63155415241212), we get a palindrome (84369666696348).

The spelling of 21214251455136 in words is "twenty-one trillion, two hundred fourteen billion, two hundred fifty-one million, four hundred fifty-five thousand, one hundred thirty-six".