21724063542 has 16 divisors (see below), whose sum is σ = 48275696880. Its totient is φ = 7241354496.

The previous prime is 21724063541. The next prime is 21724063597. The reversal of 21724063542 is 24536042712.

21724063542 is a `hidden beast` number, since 2 + 1 + 72 + 40 + 6 + 3 + 542 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 21724063497 and 21724063506.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21724063541) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 201148683 + ... + 201148790.

It is an arithmetic number, because the mean of its divisors is an integer number (3017231055).

Almost surely, 2^21724063542 is an apocalyptic number.

21724063542 is an abundant number, since it is smaller than the sum of its proper divisors (26551633338).

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

21724063542 is a wasteful number, since it uses less digits than its factorization.

21724063542 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 402297484 (or 402297478 counting only the distinct ones).

The product of its (nonzero) digits is 80640, while the sum is 36.

The spelling of 21724063542 in words is "twenty-one billion, seven hundred twenty-four million, sixty-three thousand, five hundred forty-two".