21163425 has 24 divisors (see below), whose sum is σ = 35206080. Its totient is φ = 11217600.

The previous prime is 21163411. The next prime is 21163433. The reversal of 21163425 is 52436112.

It is not a de Polignac number, because 21163425 - 2⁶ = 21163361 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21163395 and 21163404.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 12796 + ... + 14354.

It is an arithmetic number, because the mean of its divisors is an integer number (1466920).

Almost surely, 2^21163425 is an apocalyptic number.

21163425 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21163425 is a deficient number, since it is larger than the sum of its proper divisors (14042655).

21163425 is a wasteful number, since it uses less digits than its factorization.

21163425 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1753 (or 1748 counting only the distinct ones).

The product of its digits is 1440, while the sum is 24.

The square root of 21163425 is about 4600.3722675453. The cubic root of 21163425 is about 276.6062471892.

Adding to 21163425 its reverse (52436112), we get a palindrome (73599537).

It can be divided in two parts, 211 and 63425, that added together give a palindrome (63636).

The spelling of 21163425 in words is "twenty-one million, one hundred sixty-three thousand, four hundred twenty-five".