78621349 has 4 divisors (see below), whose sum is σ = 81332460. Its totient is φ = 75910240.

The previous prime is 78621331. The next prime is 78621371. The reversal of 78621349 is 94312687.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 42837025 + 35784324 = 6545^2 + 5982^2 .

It is a cyclic number.

It is not a de Polignac number, because 78621349 - 2⁵ = 78621317 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 (78621649) 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, 1355512 + ... + 1355569.

It is an arithmetic number, because the mean of its divisors is an integer number (20333115).

Almost surely, 2^78621349 is an apocalyptic number.

It is an amenable number.

78621349 is a deficient number, since it is larger than the sum of its proper divisors (2711111).

78621349 is a wasteful number, since it uses less digits than its factorization.

78621349 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2711110.

The product of its digits is 72576, while the sum is 40.

The square root of 78621349 is about 8866.8680490915. The cubic root of 78621349 is about 428.3974039858.

The spelling of 78621349 in words is "seventy-eight million, six hundred twenty-one thousand, three hundred forty-nine".