21251050 has 24 divisors (see below), whose sum is σ = 40372416. Its totient is φ = 8318640.

The previous prime is 21251023. The next prime is 21251053. The reversal of 21251050 is 5015212.

It is a super-2 number, since 2×21251050² = 903214252205000, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21251053) 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 11 ways as a sum of consecutive naturals, for example, 2172 + ... + 6871.

It is an arithmetic number, because the mean of its divisors is an integer number (1682184).

Almost surely, 2^21251050 is an apocalyptic number.

21251050 is a deficient number, since it is larger than the sum of its proper divisors (19121366).

21251050 is a wasteful number, since it uses less digits than its factorization.

21251050 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9102 (or 9097 counting only the distinct ones).

The product of its (nonzero) digits is 100, while the sum is 16.

The square root of 21251050 is about 4609.8861157300. The cubic root of 21251050 is about 276.9874748341.

Adding to 21251050 its reverse (5015212), we get a palindrome (26266262).

The spelling of 21251050 in words is "twenty-one million, two hundred fifty-one thousand, fifty".