21123201125 has 64 divisors (see below), whose sum is σ = 28953759744. Its totient is φ = 15291360000.

The previous prime is 21123201119. The next prime is 21123201157. The reversal of 21123201125 is 52110232112.

It is not a de Polignac number, because 21123201125 - 2⁸ = 21123200869 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21123201097 and 21123201106.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 25728215 + ... + 25729035.

It is an arithmetic number, because the mean of its divisors is an integer number (452402496).

Almost surely, 2^21123201125 is an apocalyptic number.

21123201125 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21123201125 is a deficient number, since it is larger than the sum of its proper divisors (7830558619).

21123201125 is a wasteful number, since it uses less digits than its factorization.

21123201125 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1143 (or 1133 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 20.

Adding to 21123201125 its reverse (52110232112), we get a palindrome (73233433237).

The spelling of 21123201125 in words is "twenty-one billion, one hundred twenty-three million, two hundred one thousand, one hundred twenty-five".