13978037509 has 4 divisors (see below), whose sum is σ = 13980502816. Its totient is φ = 13975572204.

The previous prime is 13978037473. The next prime is 13978037531. The reversal of 13978037509 is 90573087931.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-13978037509 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13978037539) 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, 1224129 + ... + 1235494.

It is an arithmetic number, because the mean of its divisors is an integer number (3495125704).

Almost surely, 2^13978037509 is an apocalyptic number.

It is an amenable number.

13978037509 is a deficient number, since it is larger than the sum of its proper divisors (2465307).

13978037509 is an equidigital number, since it uses as much as digits as its factorization.

13978037509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2465306.

The product of its (nonzero) digits is 1428840, while the sum is 52.

The spelling of 13978037509 in words is "thirteen billion, nine hundred seventy-eight million, thirty-seven thousand, five hundred nine".