13780978 has 8 divisors (see below), whose sum is σ = 20786220. Its totient is φ = 6852240.

The previous prime is 13780973. The next prime is 13780993. The reversal of 13780978 is 87908731.

It can be written as a sum of positive squares in 2 ways, for example, as 12794929 + 986049 = 3577^2 + 993^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (13780973) 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 in 3 ways as a sum of consecutive naturals, for example, 18673 + ... + 19396.

Almost surely, 2^13780978 is an apocalyptic number.

13780978 is a deficient number, since it is larger than the sum of its proper divisors (7005242).

13780978 is a wasteful number, since it uses less digits than its factorization.

13780978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38252.

The product of its (nonzero) digits is 84672, while the sum is 43.

The square root of 13780978 is about 3712.2739661830. The cubic root of 13780978 is about 239.7507713701.

The spelling of 13780978 in words is "thirteen million, seven hundred eighty thousand, nine hundred seventy-eight".