13780649 has 4 divisors (see below), whose sum is σ = 13812480. Its totient is φ = 13748820.

The previous prime is 13780631. The next prime is 13780651. The reversal of 13780649 is 94608731.

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, and also an emirpimes, since its reverse is a distinct semiprime: 94608731 = 7 ⋅13515533.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-13780649 is a prime.

It is a super-2 number, since 2×13780649² = 379812573722402, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (13780609) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15257 + ... + 16134.

It is an arithmetic number, because the mean of its divisors is an integer number (3453120).

Almost surely, 2^13780649 is an apocalyptic number.

It is an amenable number.

13780649 is a deficient number, since it is larger than the sum of its proper divisors (31831).

13780649 is an equidigital number, since it uses as much as digits as its factorization.

13780649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31830.

The product of its (nonzero) digits is 36288, while the sum is 38.

The square root of 13780649 is about 3712.2296534563. The cubic root of 13780649 is about 239.7488634592.

The spelling of 13780649 in words is "thirteen million, seven hundred eighty thousand, six hundred forty-nine".