21612712141240 has 128 divisors (see below), whose sum is σ = 53780234731200. Its totient is φ = 7750910545920.

The previous prime is 21612712141159. The next prime is 21612712141247. The reversal of 21612712141240 is 4214121721612.

It is a super-2 number, since 2×21612712141240² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21612712141196 and 21612712141205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21612712141247) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 825246066 + ... + 825272254.

Almost surely, 2^{21612712141240} is an apocalyptic number.

21612712141240 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 21612712141240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26890117365600).

21612712141240 is an abundant number, since it is smaller than the sum of its proper divisors (32167522589960).

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

21612712141240 is a wasteful number, since it uses less digits than its factorization.

21612712141240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51977 (or 51973 counting only the distinct ones).

The product of its (nonzero) digits is 10752, while the sum is 34.

Adding to 21612712141240 its reverse (4214121721612), we get a palindrome (25826833862852).

The spelling of 21612712141240 in words is "twenty-one trillion, six hundred twelve billion, seven hundred twelve million, one hundred forty-one thousand, two hundred forty".