21143135434542 has 128 divisors (see below), whose sum is σ = 49230965514240. Its totient is φ = 5985753603840.

The previous prime is 21143135434501. The next prime is 21143135434549. The reversal of 21143135434542 is 24543453134112.

It is a junction number, because it is equal to n+sod(n) for n = 21143135434494 and 21143135434503.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21143135434549) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 824505973 + ... + 824531615.

It is an arithmetic number, because the mean of its divisors is an integer number (384616918080).

Almost surely, 2^{21143135434542} is an apocalyptic number.

21143135434542 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 21143135434542, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24615482757120).

21143135434542 is an abundant number, since it is smaller than the sum of its proper divisors (28087830079698).

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

21143135434542 is a wasteful number, since it uses less digits than its factorization.

21143135434542 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34758.

The product of its digits is 691200, while the sum is 42.

Adding to 21143135434542 its reverse (24543453134112), we get a palindrome (45686588568654).

The spelling of 21143135434542 in words is "twenty-one trillion, one hundred forty-three billion, one hundred thirty-five million, four hundred thirty-four thousand, five hundred forty-two".