20478725 has 6 divisors (see below), whose sum is σ = 25393650. Its totient is φ = 16382960.

The previous prime is 20478719. The next prime is 20478739. The reversal of 20478725 is 52787402.

It can be written as a sum of positive squares in 3 ways, for example, as 111556 + 20367169 = 334^2 + 4513^2 .

It is a de Polignac number, because none of the positive numbers 2^k-20478725 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 409550 + ... + 409599.

It is an arithmetic number, because the mean of its divisors is an integer number (4232275).

Almost surely, 2^20478725 is an apocalyptic number.

20478725 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

20478725 is a deficient number, since it is larger than the sum of its proper divisors (4914925).

20478725 is an equidigital number, since it uses as much as digits as its factorization.

20478725 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 819159 (or 819154 counting only the distinct ones).

The product of its (nonzero) digits is 31360, while the sum is 35.

The square root of 20478725 is about 4525.3425284723. The cubic root of 20478725 is about 273.5904736959.

The spelling of 20478725 in words is "twenty million, four hundred seventy-eight thousand, seven hundred twenty-five".