21101223634 has 8 divisors (see below), whose sum is σ = 32085422460. Its totient is φ = 10406082816.

The previous prime is 21101223607. The next prime is 21101223641. The reversal of 21101223634 is 43632210112.

21101223634 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 20553523225 + 547700409 = 143365^2 + 23403^2 .

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

It is a junction number, because it is equal to n+sod(n) for n = 21101223599 and 21101223608.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 72264319 + ... + 72264610.

Almost surely, 2^21101223634 is an apocalyptic number.

21101223634 is a deficient number, since it is larger than the sum of its proper divisors (10984198826).

21101223634 is a wasteful number, since it uses less digits than its factorization.

21101223634 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 144529004.

The product of its (nonzero) digits is 1728, while the sum is 25.

Adding to 21101223634 its reverse (43632210112), we get a palindrome (64733433746).

The spelling of 21101223634 in words is "twenty-one billion, one hundred one million, two hundred twenty-three thousand, six hundred thirty-four".