163540031012521 has 4 divisors (see below), whose sum is σ = 163578429709200. Its totient is φ = 163501632315844.

The previous prime is 163540031012509. The next prime is 163540031012537. The reversal of 163540031012521 is 125210130045361.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-163540031012521 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (163540031016521) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19199341951 + ... + 19199350468.

It is an arithmetic number, because the mean of its divisors is an integer number (40894607427300).

Almost surely, 2^{163540031012521} is an apocalyptic number.

It is an amenable number.

163540031012521 is a deficient number, since it is larger than the sum of its proper divisors (38398696679).

163540031012521 is an equidigital number, since it uses as much as digits as its factorization.

163540031012521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38398696678.

The product of its (nonzero) digits is 21600, while the sum is 34.

Adding to 163540031012521 its reverse (125210130045361), we get a palindrome (288750161057882).

The spelling of 163540031012521 in words is "one hundred sixty-three trillion, five hundred forty billion, thirty-one million, twelve thousand, five hundred twenty-one".