13539021791 has 4 divisors (see below), whose sum is σ = 13543126584. Its totient is φ = 13534917000.

The previous prime is 13539021787. The next prime is 13539021841. The reversal of 13539021791 is 19712093531.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 13539021791 - 2² = 13539021787 is a prime.

It is a super-2 number, since 2×13539021791² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13539021701) 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, 2047445 + ... + 2054046.

It is an arithmetic number, because the mean of its divisors is an integer number (3385781646).

Almost surely, 2^13539021791 is an apocalyptic number.

13539021791 is a deficient number, since it is larger than the sum of its proper divisors (4104793).

13539021791 is an equidigital number, since it uses as much as digits as its factorization.

13539021791 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4104792.

The product of its (nonzero) digits is 51030, while the sum is 41.

The spelling of 13539021791 in words is "thirteen billion, five hundred thirty-nine million, twenty-one thousand, seven hundred ninety-one".