78152720 has 20 divisors (see below), whose sum is σ = 181705260. Its totient is φ = 31261056.

The previous prime is 78152677. The next prime is 78152729. The reversal of 78152720 is 2725187.

It can be written as a sum of positive squares in 2 ways, for example, as 9461776 + 68690944 = 3076^2 + 8288^2 .

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

It is a super-2 number, since 2×78152720² = 12215695286796800, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (78152729) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 488375 + ... + 488534.

It is an arithmetic number, because the mean of its divisors is an integer number (9085263).

Almost surely, 2^78152720 is an apocalyptic number.

It is an amenable number.

78152720 is an abundant number, since it is smaller than the sum of its proper divisors (103552540).

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

78152720 is a wasteful number, since it uses less digits than its factorization.

78152720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 976922 (or 976916 counting only the distinct ones).

The product of its (nonzero) digits is 7840, while the sum is 32.

The square root of 78152720 is about 8840.4027057595. The cubic root of 78152720 is about 427.5445412592.

The spelling of 78152720 in words is "seventy-eight million, one hundred fifty-two thousand, seven hundred twenty".