21421105355542 has 16 divisors (see below), whose sum is σ = 32503643857440. Its totient is φ = 10586834489088.

The previous prime is 21421105355539. The next prime is 21421105355557. The reversal of 21421105355542 is 24555350112412.

It is a super-2 number, since 2×21421105355542² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21421105355495 and 21421105355504.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 69116442 + ... + 69425677.

It is an arithmetic number, because the mean of its divisors is an integer number (2031477741090).

Almost surely, 2^{21421105355542} is an apocalyptic number.

21421105355542 is a deficient number, since it is larger than the sum of its proper divisors (11082538501898).

21421105355542 is a wasteful number, since it uses less digits than its factorization.

21421105355542 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 138543015.

The product of its (nonzero) digits is 240000, while the sum is 40.

Adding to 21421105355542 its reverse (24555350112412), we get a palindrome (45976455467954).

The spelling of 21421105355542 in words is "twenty-one trillion, four hundred twenty-one billion, one hundred five million, three hundred fifty-five thousand, five hundred forty-two".