78349520 has 20 divisors (see below), whose sum is σ = 182162820. Its totient is φ = 31339776.

The previous prime is 78349507. The next prime is 78349547. The reversal of 78349520 is 2594387.

It can be written as a sum of positive squares in 2 ways, for example, as 15178816 + 63170704 = 3896^2 + 7948^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a super-2 number, since 2×78349520² = 12277294568460800, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

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, 489605 + ... + 489764.

It is an arithmetic number, because the mean of its divisors is an integer number (9108141).

Almost surely, 2^78349520 is an apocalyptic number.

It is an amenable number.

78349520 is an abundant number, since it is smaller than the sum of its proper divisors (103813300).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

78349520 is a wasteful number, since it uses less digits than its factorization.

78349520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 979382 (or 979376 counting only the distinct ones).

The product of its (nonzero) digits is 60480, while the sum is 38.

The square root of 78349520 is about 8851.5264220359. The cubic root of 78349520 is about 427.9031137146.

The spelling of 78349520 in words is "seventy-eight million, three hundred forty-nine thousand, five hundred twenty".