21025144 has 16 divisors (see below), whose sum is σ = 45054000. Its totient is φ = 9010752.

The previous prime is 21025129. The next prime is 21025157. The reversal of 21025144 is 44152012.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 187669 + ... + 187780.

It is an arithmetic number, because the mean of its divisors is an integer number (2815875).

Almost surely, 2^21025144 is an apocalyptic number.

It is an amenable number.

21025144 is an abundant number, since it is smaller than the sum of its proper divisors (24028856).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21025144 is a wasteful number, since it uses less digits than its factorization.

21025144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 375462 (or 375458 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 19.

The square root of 21025144 is about 4585.3183095615. The cubic root of 21025144 is about 276.0024854499.

Adding to 21025144 its reverse (44152012), we get a palindrome (65177156).

It can be divided in two parts, 21025 and 144, that multiplied together give a square (3027600 = 1740²).

The spelling of 21025144 in words is "twenty-one million, twenty-five thousand, one hundred forty-four".