78187136 has 16 divisors (see below), whose sum is σ = 155763690. Its totient is φ = 39093504.

The previous prime is 78187129. The next prime is 78187157. The reversal of 78187136 is 63178187.

It can be written as a sum of positive squares in only one way, i.e., 73960000 + 4227136 = 8600^2 + 2056^2 .

It is a tau number, because it is divible by the number of its divisors (16).

It is a super-2 number, since 2×78187136² = 12226456471764992, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 78187093 and 78187102.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 305291 + ... + 305546.

Almost surely, 2^78187136 is an apocalyptic number.

It is an amenable number.

78187136 is a deficient number, since it is larger than the sum of its proper divisors (77576554).

78187136 is an equidigital number, since it uses as much as digits as its factorization.

78187136 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 610851 (or 610839 counting only the distinct ones).

The product of its digits is 56448, while the sum is 41.

The square root of 78187136 is about 8842.3490091717. The cubic root of 78187136 is about 427.6072911057.

The spelling of 78187136 in words is "seventy-eight million, one hundred eighty-seven thousand, one hundred thirty-six".