78077550 has 48 divisors (see below), whose sum is σ = 194563440. Its totient is φ = 20720640.

The previous prime is 78077521. The next prime is 78077557. The reversal of 78077550 is 5577087.

It is a super-2 number, since 2×78077550² = 12192207628005000, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 78077499 and 78077508.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78077557) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 33214 + ... + 35486.

It is an arithmetic number, because the mean of its divisors is an integer number (4053405).

Almost surely, 2^78077550 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 78077550, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (97281720).

78077550 is an abundant number, since it is smaller than the sum of its proper divisors (116485890).

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

78077550 is a wasteful number, since it uses less digits than its factorization.

78077550 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2517 (or 2512 counting only the distinct ones).

The product of its (nonzero) digits is 68600, while the sum is 39.

The square root of 78077550 is about 8836.1501798012. The cubic root of 78077550 is about 427.4074215588.

The spelling of 78077550 in words is "seventy-eight million, seventy-seven thousand, five hundred fifty".