21203120131 has 8 divisors (see below), whose sum is σ = 21799050944. Its totient is φ = 20611863720.

The previous prime is 21203120123. The next prime is 21203120143. The reversal of 21203120131 is 13102130212.

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 21203120131 - 2³ = 21203120123 is a prime.

It is a super-2 number, since 2×21203120131² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21203120161) 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 7 ways as a sum of consecutive naturals, for example, 1159401 + ... + 1177546.

It is an arithmetic number, because the mean of its divisors is an integer number (2724881368).

Almost surely, 2^21203120131 is an apocalyptic number.

21203120131 is a deficient number, since it is larger than the sum of its proper divisors (595930813).

21203120131 is a wasteful number, since it uses less digits than its factorization.

21203120131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2337201.

The product of its (nonzero) digits is 72, while the sum is 16.

Adding to 21203120131 its reverse (13102130212), we get a palindrome (34305250343).

The spelling of 21203120131 in words is "twenty-one billion, two hundred three million, one hundred twenty thousand, one hundred thirty-one".