21051310 has 16 divisors (see below), whose sum is σ = 43305696. Its totient is φ = 7217568.

The previous prime is 21051271. The next prime is 21051311. The reversal of 21051310 is 1315012.

It is a super-2 number, since 2×21051310² = 886315305432200, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21051311) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 150297 + ... + 150436.

It is an arithmetic number, because the mean of its divisors is an integer number (2706606).

Almost surely, 2^21051310 is an apocalyptic number.

21051310 is an abundant number, since it is smaller than the sum of its proper divisors (22254386).

21051310 is a wasteful number, since it uses less digits than its factorization.

21051310 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 300747.

The product of its (nonzero) digits is 30, while the sum is 13.

The square root of 21051310 is about 4588.1706594241. The cubic root of 21051310 is about 276.1169339280.

Adding to 21051310 its reverse (1315012), we get a palindrome (22366322).

The spelling of 21051310 in words is "twenty-one million, fifty-one thousand, three hundred ten".