78643725 has 12 divisors (see below), whose sum is σ = 130024416. Its totient is φ = 41943280.

The previous prime is 78643723. The next prime is 78643769. The reversal of 78643725 is 52734687.

It is not a de Polignac number, because 78643725 - 2¹ = 78643723 is a prime.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78643723) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 524217 + ... + 524366.

It is an arithmetic number, because the mean of its divisors is an integer number (10835368).

Almost surely, 2^78643725 is an apocalyptic number.

78643725 is a gapful number since it is divisible by the number (75) formed by its first and last digit.

It is an amenable number.

78643725 is a deficient number, since it is larger than the sum of its proper divisors (51380691).

78643725 is a wasteful number, since it uses less digits than its factorization.

78643725 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1048596 (or 1048591 counting only the distinct ones).

The product of its digits is 282240, while the sum is 42.

The square root of 78643725 is about 8868.1297351809. The cubic root of 78643725 is about 428.4380414258.

The spelling of 78643725 in words is "seventy-eight million, six hundred forty-three thousand, seven hundred twenty-five".