13489972981 has 4 divisors (see below), whose sum is σ = 13490281132. Its totient is φ = 13489664832.

The previous prime is 13489972973. The next prime is 13489972987. The reversal of 13489972981 is 18927998431.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 18927998431 = 227 ⋅83383253.

It can be written as a sum of positive squares in 2 ways, for example, as 5755649956 + 7734323025 = 75866^2 + 87945^2 .

It is a cyclic number.

It is not a de Polignac number, because 13489972981 - 2³ = 13489972973 is a prime.

It is a super-2 number, since 2×13489972981² (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 (13489972987) 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, 74820 + ... + 180493.

It is an arithmetic number, because the mean of its divisors is an integer number (3372570283).

Almost surely, 2^13489972981 is an apocalyptic number.

It is an amenable number.

13489972981 is a deficient number, since it is larger than the sum of its proper divisors (308151).

13489972981 is an equidigital number, since it uses as much as digits as its factorization.

13489972981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 308150.

The product of its digits is 7838208, while the sum is 61.

The spelling of 13489972981 in words is "thirteen billion, four hundred eighty-nine million, nine hundred seventy-two thousand, nine hundred eighty-one".