13520340729 has 63 divisors (see below), whose sum is σ = 22987665103. Its totient is φ = 7657538112.

The previous prime is 13520340721. The next prime is 13520340733. The reversal of 13520340729 is 92704302531.

The square root of 13520340729 is 116277.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 238239225 + 13282101504 = 15435^2 + 115248^2 .

It is a tau number, because it is divible by the number of its divisors (63).

It is not a de Polignac number, because 13520340729 - 2³ = 13520340721 is a prime.

It is a super-2 number, since 2×13520340729² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 13520340693 and 13520340702.

It is not an unprimeable number, because it can be changed into a prime (13520340721) by changing a digit.

It is a polite number, since it can be written in 62 ways as a sum of consecutive naturals, for example, 119648977 + ... + 119649089.

Almost surely, 2^13520340729 is an apocalyptic number.

13520340729 is the 116277-th square number.

13520340729 is the 58139-th centered octagonal number.

It is an amenable number.

13520340729 is a deficient number, since it is larger than the sum of its proper divisors (9467324374).

13520340729 is an frugal number, since it uses more digits than its factorization.

13520340729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 274 (or 123 counting only the distinct ones).

The product of its (nonzero) digits is 45360, while the sum is 36.

Multiplying 13520340729 by its sum of digits (36), we get a square (486732266244 = 697662²).

The spelling of 13520340729 in words is "thirteen billion, five hundred twenty million, three hundred forty thousand, seven hundred twenty-nine".