21203123131 has 8 divisors (see below), whose sum is σ = 22740192720. Its totient is φ = 19708165152.

The previous prime is 21203123119. The next prime is 21203123143. The reversal of 21203123131 is 13132130212.

It is an interprime number because it is at equal distance from previous prime (21203123119) and next prime (21203123143).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21203123131 - 2⁵ = 21203123099 is a prime.

It is a super-2 number, since 2×21203123131² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (19).

It is a junction number, because it is equal to n+sod(n) for n = 21203123099 and 21203123108.

It is not an unprimeable number, because it can be changed into a prime (21203123731) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10526860 + ... + 10528873.

It is an arithmetic number, because the mean of its divisors is an integer number (2842524090).

Almost surely, 2^21203123131 is an apocalyptic number.

21203123131 is a deficient number, since it is larger than the sum of its proper divisors (1537069589).

21203123131 is a wasteful number, since it uses less digits than its factorization.

21203123131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21055805.

The product of its (nonzero) digits is 216, while the sum is 19.

Adding to 21203123131 its reverse (13132130212), we get a palindrome (34335253343).

The spelling of 21203123131 in words is "twenty-one billion, two hundred three million, one hundred twenty-three thousand, one hundred thirty-one".