21101101025 has 24 divisors (see below), whose sum is σ = 27312013824. Its totient is φ = 16141593600.

The previous prime is 21101101009. The next prime is 21101101027. The reversal of 21101101025 is 52010110112.

It is not a de Polignac number, because 21101101025 - 2⁴ = 21101101009 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21101101027) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3326657 + ... + 3332993.

It is an arithmetic number, because the mean of its divisors is an integer number (1138000576).

Almost surely, 2^21101101025 is an apocalyptic number.

21101101025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21101101025 is a deficient number, since it is larger than the sum of its proper divisors (6210912799).

21101101025 is a wasteful number, since it uses less digits than its factorization.

21101101025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12161 (or 12156 counting only the distinct ones).

The product of its (nonzero) digits is 20, while the sum is 14.

Adding to 21101101025 its reverse (52010110112), we get a palindrome (73111211137).

The spelling of 21101101025 in words is "twenty-one billion, one hundred one million, one hundred one thousand, twenty-five".