21120213155540 has 48 divisors (see below), whose sum is σ = 45958440528000. Its totient is φ = 8143154527872.

The previous prime is 21120213155519. The next prime is 21120213155549. The reversal of 21120213155540 is 4555131202112.

It is a super-3 number, since 3×21120213155540³ (a number of 41 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21120213155497 and 21120213155506.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21120213155549) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 30048374 + ... + 30743213.

It is an arithmetic number, because the mean of its divisors is an integer number (957467511000).

Almost surely, 2^{21120213155540} is an apocalyptic number.

21120213155540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21120213155540 is an abundant number, since it is smaller than the sum of its proper divisors (24838227372460).

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

21120213155540 is a wasteful number, since it uses less digits than its factorization.

21120213155540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60792224 (or 60792222 counting only the distinct ones).

The product of its (nonzero) digits is 12000, while the sum is 32.

Adding to 21120213155540 its reverse (4555131202112), we get a palindrome (25675344357652).

The spelling of 21120213155540 in words is "twenty-one trillion, one hundred twenty billion, two hundred thirteen million, one hundred fifty-five thousand, five hundred forty".