21045319542 has 72 divisors (see below), whose sum is σ = 49445878248. Its totient is φ = 6466262400.

The previous prime is 21045319531. The next prime is 21045319597. The reversal of 21045319542 is 24591354012.

21045319542 is a `hidden beast` number, since 2 + 10 + 453 + 195 + 4 + 2 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 21045319497 and 21045319506.

It is a congruent number.

It is an unprimeable number.

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 35 ways as a sum of consecutive naturals, for example, 2310417 + ... + 2319507.

It is an arithmetic number, because the mean of its divisors is an integer number (686748309).

Almost surely, 2^21045319542 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21045319542, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24722939124).

21045319542 is an abundant number, since it is smaller than the sum of its proper divisors (28400558706).

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

21045319542 is a wasteful number, since it uses less digits than its factorization.

21045319542 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9886 (or 9870 counting only the distinct ones).

The product of its (nonzero) digits is 43200, while the sum is 36.

The spelling of 21045319542 in words is "twenty-one billion, forty-five million, three hundred nineteen thousand, five hundred forty-two".