21230312131 has 32 divisors (see below), whose sum is σ = 26657164800.
Its totient is φ = 16501605120.
The previous prime is 21230312107. The next prime is 21230312209. The reversal of 21230312131 is 13121303212.
It is not a de Polignac number, because 21230312131 - 25 = 21230312099 is a prime.
It is a super-2 number, since 2×212303121312 (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 = 21230312099 and 21230312108.
It is not an unprimeable number, because it can be changed into a prime (21230312101) by changing a digit.
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 31 ways as a sum of consecutive naturals, for example, 252280 + ... + 325738.
It is an arithmetic number, because the mean of its divisors is an integer number (833036400).
Almost surely, 221230312131 is an apocalyptic number.
21230312131 is a deficient number, since it is larger than the sum of its proper divisors (5426852669).
21230312131 is a wasteful number, since it uses less digits than its factorization.
21230312131 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 73579.
The product of its (nonzero) digits is 216, while the sum is 19.
Adding to 21230312131 its reverse (13121303212), we get a palindrome (34351615343).
The spelling of 21230312131 in words is "twenty-one billion, two hundred thirty million, three hundred twelve thousand, one hundred thirty-one".