21126655635 has 16 divisors (see below), whose sum is σ = 35272329984. Its totient is φ = 10777656032.

The previous prime is 21126655621. The next prime is 21126655691. The reversal of 21126655635 is 53655662112.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21126655635 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 30617997 + ... + 30618686.

It is an arithmetic number, because the mean of its divisors is an integer number (2204520624).

Almost surely, 2^21126655635 is an apocalyptic number.

21126655635 is a deficient number, since it is larger than the sum of its proper divisors (14145674349).

21126655635 is a wasteful number, since it uses less digits than its factorization.

21126655635 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61236714.

The product of its digits is 324000, while the sum is 42.

The spelling of 21126655635 in words is "twenty-one billion, one hundred twenty-six million, six hundred fifty-five thousand, six hundred thirty-five".