13139968 has 32 divisors (see below), whose sum is σ = 26345070. Its totient is φ = 6553600.

The previous prime is 13139947. The next prime is 13139989. The reversal of 13139968 is 86993131.

It is an interprime number because it is at equal distance from previous prime (13139947) and next prime (13139989).

It can be written as a sum of positive squares in only one way, i.e., 7225344 + 5914624 = 2688^2 + 2432^2 .

It is a tau number, because it is divible by the number of its divisors (32).

It is a nialpdrome in base 8 and base 16.

It is a self number, because there is not a number n which added to its sum of digits gives 13139968.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32568 + ... + 32968.

Almost surely, 2^13139968 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 13139968, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (13172535).

13139968 is an abundant number, since it is smaller than the sum of its proper divisors (13205102).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

13139968 is an frugal number, since it uses more digits than its factorization.

13139968 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 431 (or 403 counting only the distinct ones).

The product of its digits is 34992, while the sum is 40.

The square root of 13139968 is about 3624.9093781776. The cubic root of 13139968 is about 235.9743340852.

The spelling of 13139968 in words is "thirteen million, one hundred thirty-nine thousand, nine hundred sixty-eight".