13978969 has 2 divisors, whose sum is σ = 13978970. Its totient is φ = 13978968.

The previous prime is 13978967. The next prime is 13978997. The reversal of 13978969 is 96987931.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13505625 + 473344 = 3675^2 + 688^2 .

It is a cyclic number.

It is not a de Polignac number, because 13978969 - 2¹ = 13978967 is a prime.

It is a super-2 number, since 2×13978969² = 390823148605922, which contains 22 as substring.

Together with 13978967, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (13978967) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6989484 + 6989485.

It is an arithmetic number, because the mean of its divisors is an integer number (6989485).

Almost surely, 2^13978969 is an apocalyptic number.

It is an amenable number.

13978969 is a deficient number, since it is larger than the sum of its proper divisors (1).

13978969 is an equidigital number, since it uses as much as digits as its factorization.

13978969 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 734832, while the sum is 52.

The square root of 13978969 is about 3738.8459449408. The cubic root of 13978969 is about 240.8934809308.

The spelling of 13978969 in words is "thirteen million, nine hundred seventy-eight thousand, nine hundred sixty-nine".