21123020313 has 24 divisors (see below), whose sum is σ = 30766632000. Its totient is φ = 13964357664.

The previous prime is 21123020299. The next prime is 21123020327. The reversal of 21123020313 is 31302032112.

It is an interprime number because it is at equal distance from previous prime (21123020299) and next prime (21123020327).

It is not a de Polignac number, because 21123020313 - 2⁶ = 21123020249 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21123020363) 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, 817356 + ... + 842802.

It is an arithmetic number, because the mean of its divisors is an integer number (1281943000).

Almost surely, 2^21123020313 is an apocalyptic number.

It is an amenable number.

21123020313 is a deficient number, since it is larger than the sum of its proper divisors (9643611687).

21123020313 is a wasteful number, since it uses less digits than its factorization.

21123020313 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26221 (or 26218 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 18.

Adding to 21123020313 its reverse (31302032112), we get a palindrome (52425052425).

The spelling of 21123020313 in words is "twenty-one billion, one hundred twenty-three million, twenty thousand, three hundred thirteen".