78877825 has 24 divisors (see below), whose sum is σ = 108977400. Its totient is φ = 56232960.

The previous prime is 78877823. The next prime is 78877831. The reversal of 78877825 is 52877887.

It is a happy number.

It can be written as a sum of positive squares in 12 ways, for example, as 25280784 + 53597041 = 5028^2 + 7321^2 .

It is not a de Polignac number, because 78877825 - 2¹ = 78877823 is a prime.

It is a super-2 number, since 2×78877825² = 12443422553461250, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (78877823) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 5241 + ... + 13609.

It is an arithmetic number, because the mean of its divisors is an integer number (4540725).

Almost surely, 2^78877825 is an apocalyptic number.

It is an amenable number.

78877825 is a deficient number, since it is larger than the sum of its proper divisors (30099575).

78877825 is a wasteful number, since it uses less digits than its factorization.

78877825 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8421 (or 8416 counting only the distinct ones).

The product of its digits is 1756160, while the sum is 52.

The square root of 78877825 is about 8881.3188772839. The cubic root of 78877825 is about 428.8627330371.

The spelling of 78877825 in words is "seventy-eight million, eight hundred seventy-seven thousand, eight hundred twenty-five".