78780449 has 4 divisors (see below), whose sum is σ = 85942320. Its totient is φ = 71618580.

The previous prime is 78780439. The next prime is 78780469. The reversal of 78780449 is 94408787.

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: 94408787 = 11 ⋅8582617.

It is a de Polignac number, because none of the positive numbers 2^k-78780449 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78780439) 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, 3580919 + ... + 3580940.

It is an arithmetic number, because the mean of its divisors is an integer number (21485580).

Almost surely, 2^78780449 is an apocalyptic number.

It is an amenable number.

78780449 is a deficient number, since it is larger than the sum of its proper divisors (7161871).

78780449 is a wasteful number, since it uses less digits than its factorization.

78780449 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7161870.

The product of its (nonzero) digits is 451584, while the sum is 47.

The square root of 78780449 is about 8875.8351156384. The cubic root of 78780449 is about 428.6861809489.

The spelling of 78780449 in words is "seventy-eight million, seven hundred eighty thousand, four hundred forty-nine".