78243525 has 36 divisors (see below), whose sum is σ = 140713092. Its totient is φ = 41560320.

The previous prime is 78243523. The next prime is 78243553. The reversal of 78243525 is 52534287.

It can be written as a sum of positive squares in 6 ways, for example, as 19766916 + 58476609 = 4446^2 + 7647^2 .

It is not a de Polignac number, because 78243525 - 2¹ = 78243523 is a prime.

It is a super-2 number, since 2×78243525² = 12244098408851250, which contains 22 as substring.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 78243525.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78243523) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 70777 + ... + 71873.

It is an arithmetic number, because the mean of its divisors is an integer number (3908697).

Almost surely, 2^78243525 is an apocalyptic number.

78243525 is a gapful number since it is divisible by the number (75) formed by its first and last digit.

It is an amenable number.

78243525 is a deficient number, since it is larger than the sum of its proper divisors (62469567).

78243525 is a wasteful number, since it uses less digits than its factorization.

78243525 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1430 (or 1422 counting only the distinct ones).

The product of its digits is 67200, while the sum is 36.

The square root of 78243525 is about 8845.5370102668. The cubic root of 78243525 is about 427.7100639933.

The spelling of 78243525 in words is "seventy-eight million, two hundred forty-three thousand, five hundred twenty-five".