78191725 has 6 divisors (see below), whose sum is σ = 96957770. Its totient is φ = 62553360.

The previous prime is 78191699. The next prime is 78191731. The reversal of 78191725 is 52719187.

It can be written as a sum of positive squares in 3 ways, for example, as 1085764 + 77105961 = 1042^2 + 8781^2 .

It is not a de Polignac number, because 78191725 - 2¹¹ = 78189677 is a prime.

It is a super-2 number, since 2×78191725² = 12227891716951250, 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 (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1563810 + ... + 1563859.

Almost surely, 2^78191725 is an apocalyptic number.

It is an amenable number.

78191725 is a deficient number, since it is larger than the sum of its proper divisors (18766045).

78191725 is a wasteful number, since it uses less digits than its factorization.

78191725 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3127679 (or 3127674 counting only the distinct ones).

The product of its digits is 35280, while the sum is 40.

The square root of 78191725 is about 8842.6084952349. The cubic root of 78191725 is about 427.6156567251.

The spelling of 78191725 in words is "seventy-eight million, one hundred ninety-one thousand, seven hundred twenty-five".