21401125 has 16 divisors (see below), whose sum is σ = 28117440. Its totient is φ = 16218000.

The previous prime is 21401123. The next prime is 21401137. The reversal of 21401125 is 52110412.

It is not a de Polignac number, because 21401125 - 2¹ = 21401123 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21401099 and 21401108.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21401123) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2131 + ... + 6880.

It is an arithmetic number, because the mean of its divisors is an integer number (1757340).

Almost surely, 2^21401125 is an apocalyptic number.

21401125 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21401125 is a deficient number, since it is larger than the sum of its proper divisors (6716315).

21401125 is an equidigital number, since it uses as much as digits as its factorization.

21401125 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9045 (or 9035 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 16.

The square root of 21401125 is about 4626.1349958686. The cubic root of 21401125 is about 277.6379748355.

Adding to 21401125 its reverse (52110412), we get a palindrome (73511537).

The spelling of 21401125 in words is "twenty-one million, four hundred one thousand, one hundred twenty-five".