21101308647 has 16 divisors (see below), whose sum is σ = 28689746400. Its totient is φ = 13790646272.

The previous prime is 21101308621. The next prime is 21101308649. The reversal of 21101308647 is 74680310112.

It is a cyclic number.

It is not a de Polignac number, because 21101308647 - 2¹⁴ = 21101292263 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21101308649) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 138979 + ... + 248027.

It is an arithmetic number, because the mean of its divisors is an integer number (1793109150).

Almost surely, 2^21101308647 is an apocalyptic number.

21101308647 is a deficient number, since it is larger than the sum of its proper divisors (7588437753).

21101308647 is a wasteful number, since it uses less digits than its factorization.

21101308647 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110322.

The product of its (nonzero) digits is 8064, while the sum is 33.

Adding to 21101308647 its reverse (74680310112), we get a palindrome (95781618759).

The spelling of 21101308647 in words is "twenty-one billion, one hundred one million, three hundred eight thousand, six hundred forty-seven".