126813507321 has 4 divisors (see below), whose sum is σ = 169084676432. Its totient is φ = 84542338212.

The previous prime is 126813507281. The next prime is 126813507323. The reversal of 126813507321 is 123705318621.

It is a happy number.

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, and also an emirpimes, since its reverse is a distinct semiprime: 123705318621 = 3 ⋅41235106207.

It is not a de Polignac number, because 126813507321 - 2¹⁰ = 126813506297 is a prime.

It is a super-3 number, since 3×126813507321³ (a number of 34 digits) contains 333 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 126813507321.

It is not an unprimeable number, because it can be changed into a prime (126813507323) 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, 21135584551 + ... + 21135584556.

It is an arithmetic number, because the mean of its divisors is an integer number (42271169108).

Almost surely, 2^126813507321 is an apocalyptic number.

It is an amenable number.

126813507321 is a deficient number, since it is larger than the sum of its proper divisors (42271169111).

126813507321 is an equidigital number, since it uses as much as digits as its factorization.

126813507321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42271169110.

The product of its (nonzero) digits is 60480, while the sum is 39.

The spelling of 126813507321 in words is "one hundred twenty-six billion, eight hundred thirteen million, five hundred seven thousand, three hundred twenty-one".