21642243430 has 16 divisors (see below), whose sum is σ = 39504716064. Its totient is φ = 8534968960.

The previous prime is 21642243421. The next prime is 21642243433. The reversal of 21642243430 is 3434224612.

It is a junction number, because it is equal to n+sod(n) for n = 21642243392 and 21642243401.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21642243433) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 15240307 + ... + 15241726.

It is an arithmetic number, because the mean of its divisors is an integer number (2469044754).

Almost surely, 2^21642243430 is an apocalyptic number.

21642243430 is a deficient number, since it is larger than the sum of its proper divisors (17862472634).

21642243430 is a wasteful number, since it uses less digits than its factorization.

21642243430 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30482111.

The product of its (nonzero) digits is 27648, while the sum is 31.

The spelling of 21642243430 in words is "twenty-one billion, six hundred forty-two million, two hundred forty-three thousand, four hundred thirty".