13135278721 has 16 divisors (see below), whose sum is σ = 14224464000. Its totient is φ = 12087024768.

The previous prime is 13135278713. The next prime is 13135278731. The reversal of 13135278721 is 12787253131.

It is a cyclic number.

It is not a de Polignac number, because 13135278721 - 2³ = 13135278713 is a prime.

It is not an unprimeable number, because it can be changed into a prime (13135278731) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 405501 + ... + 436693.

It is an arithmetic number, because the mean of its divisors is an integer number (889029000).

Almost surely, 2^13135278721 is an apocalyptic number.

It is an amenable number.

13135278721 is a deficient number, since it is larger than the sum of its proper divisors (1089185279).

13135278721 is a wasteful number, since it uses less digits than its factorization.

13135278721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31848.

The product of its digits is 70560, while the sum is 40.

The spelling of 13135278721 in words is "thirteen billion, one hundred thirty-five million, two hundred seventy-eight thousand, seven hundred twenty-one".