21020121310 has 16 divisors (see below), whose sum is σ = 37885951152. Its totient is φ = 8396996800.

The previous prime is 21020121307. The next prime is 21020121323. The reversal of 21020121310 is 1312102012.

It is a super-2 number, since 2×21020121310² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1373476 + ... + 1388695.

It is an arithmetic number, because the mean of its divisors is an integer number (2367871947).

Almost surely, 2^21020121310 is an apocalyptic number.

21020121310 is a deficient number, since it is larger than the sum of its proper divisors (16865829842).

21020121310 is a wasteful number, since it uses less digits than its factorization.

21020121310 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2762939.

The product of its (nonzero) digits is 24, while the sum is 13.

Adding to 21020121310 its reverse (1312102012), we get a palindrome (22332223322).

The spelling of 21020121310 in words is "twenty-one billion, twenty million, one hundred twenty-one thousand, three hundred ten".