21250136 has 64 divisors (see below), whose sum is σ = 44815680. Its totient is φ = 9400320.

The previous prime is 21250133. The next prime is 21250139. The reversal of 21250136 is 63105212.

It is an interprime number because it is at equal distance from previous prime (21250133) and next prime (21250139).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21250133) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 206261 + ... + 206363.

It is an arithmetic number, because the mean of its divisors is an integer number (700245).

Almost surely, 2^21250136 is an apocalyptic number.

It is an amenable number.

21250136 is an abundant number, since it is smaller than the sum of its proper divisors (23565544).

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

21250136 is a wasteful number, since it uses less digits than its factorization.

21250136 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 204 (or 200 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 20.

The square root of 21250136 is about 4609.7869798940. The cubic root of 21250136 is about 276.9835037333.

Adding to 21250136 its reverse (63105212), we get a palindrome (84355348).

It can be divided in two parts, 21250 and 136, that multiplied together give a square (2890000 = 1700²).

The spelling of 21250136 in words is "twenty-one million, two hundred fifty thousand, one hundred thirty-six".