21214251455140 has 96 divisors (see below), whose sum is σ = 48070469672064. Its totient is φ = 7834230343680.

The previous prime is 21214251455107. The next prime is 21214251455143. The reversal of 21214251455140 is 4155415241212.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 21214251455140.

It is not an unprimeable number, because it can be changed into a prime (21214251455143) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 88737247 + ... + 88975993.

It is an arithmetic number, because the mean of its divisors is an integer number (500734059084).

Almost surely, 2^{21214251455140} is an apocalyptic number.

21214251455140 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21214251455140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24035234836032).

21214251455140 is an abundant number, since it is smaller than the sum of its proper divisors (26856218216924).

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

21214251455140 is a wasteful number, since it uses less digits than its factorization.

21214251455140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 243757 (or 243755 counting only the distinct ones).

The product of its (nonzero) digits is 64000, while the sum is 37.

Adding to 21214251455140 its reverse (4155415241212), we get a palindrome (25369666696352).

The spelling of 21214251455140 in words is "twenty-one trillion, two hundred fourteen billion, two hundred fifty-one million, four hundred fifty-five thousand, one hundred forty".