21613567742 has 16 divisors (see below), whose sum is σ = 35274169392. Its totient is φ = 9872651520.

The previous prime is 21613567741. The next prime is 21613567747. The reversal of 21613567742 is 24776531612.

It is a happy number.

It is a Smith number, since the sum of its digits (44) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a junction number, because it is equal to n+sod(n) for n = 21613567693 and 21613567702.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21613567741) 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, 4282484 + ... + 4287527.

It is an arithmetic number, because the mean of its divisors is an integer number (2204635587).

Almost surely, 2^21613567742 is an apocalyptic number.

21613567742 is a deficient number, since it is larger than the sum of its proper divisors (13660601650).

21613567742 is a wasteful number, since it uses less digits than its factorization.

21613567742 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8570123.

The product of its digits is 423360, while the sum is 44.

The spelling of 21613567742 in words is "twenty-one billion, six hundred thirteen million, five hundred sixty-seven thousand, seven hundred forty-two".