21355454442 has 64 divisors (see below), whose sum is σ = 49801641984. Its totient is φ = 5978871360.

The previous prime is 21355454431. The next prime is 21355454467. The reversal of 21355454442 is 24445455312.

It is a self number, because there is not a number n which added to its sum of digits gives 21355454442.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 517608 + ... + 557340.

It is an arithmetic number, because the mean of its divisors is an integer number (778150656).

Almost surely, 2^21355454442 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21355454442, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24900820992).

21355454442 is an abundant number, since it is smaller than the sum of its proper divisors (28446187542).

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

21355454442 is a wasteful number, since it uses less digits than its factorization.

21355454442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40003.

The product of its digits is 384000, while the sum is 39.

The spelling of 21355454442 in words is "twenty-one billion, three hundred fifty-five million, four hundred fifty-four thousand, four hundred forty-two".