21605425422730 has 8 divisors (see below), whose sum is σ = 38889765760932. Its totient is φ = 8642170169088.

The previous prime is 21605425422727. The next prime is 21605425422739. The reversal of 21605425422730 is 3722452450612.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 21073635903609 + 531789519121 = 4590603^2 + 729239^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (21605425422739) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1080271271127 + ... + 1080271271146.

Almost surely, 2^{21605425422730} is an apocalyptic number.

21605425422730 is a deficient number, since it is larger than the sum of its proper divisors (17284340338202).

21605425422730 is a wasteful number, since it uses less digits than its factorization.

21605425422730 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2160542542280.

The product of its (nonzero) digits is 806400, while the sum is 43.

The spelling of 21605425422730 in words is "twenty-one trillion, six hundred five billion, four hundred twenty-five million, four hundred twenty-two thousand, seven hundred thirty".