21021020123013 has 24 divisors (see below), whose sum is σ = 31403329641216. Its totient is φ = 13535917761600.

The previous prime is 21021020122981. The next prime is 21021020123023. The reversal of 21021020123013 is 31032102012012.

21021020123013 is a `hidden beast` number, since 2 + 10 + 210 + 201 + 230 + 13 = 666.

It is not a de Polignac number, because 21021020123013 - 2⁵ = 21021020122981 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21021020123023) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 72161895 + ... + 72452612.

It is an arithmetic number, because the mean of its divisors is an integer number (1308472068384).

Almost surely, 2^{21021020123013} is an apocalyptic number.

It is an amenable number.

21021020123013 is a deficient number, since it is larger than the sum of its proper divisors (10382309518203).

21021020123013 is a wasteful number, since it uses less digits than its factorization.

21021020123013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 144615065 (or 144615062 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

Adding to 21021020123013 its reverse (31032102012012), we get a palindrome (52053122135025).

The spelling of 21021020123013 in words is "twenty-one trillion, twenty-one billion, twenty million, one hundred twenty-three thousand, thirteen".