1720390725 has 48 divisors (see below), whose sum is σ = 3262410240. Its totient is φ = 887932800.

The previous prime is 1720390697. The next prime is 1720390757. The reversal of 1720390725 is 5270930271.

It is not a de Polignac number, because 1720390725 - 2⁹ = 1720390213 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 1720390725.

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 47 ways as a sum of consecutive naturals, for example, 20184 + ... + 62033.

It is an arithmetic number, because the mean of its divisors is an integer number (67966880).

Almost surely, 2^1720390725 is an apocalyptic number.

1720390725 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1720390725 is a deficient number, since it is larger than the sum of its proper divisors (1542019515).

1720390725 is a wasteful number, since it uses less digits than its factorization.

1720390725 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 82267 (or 82256 counting only the distinct ones).

The product of its (nonzero) digits is 26460, while the sum is 36.

The square root of 1720390725 is about 41477.5930473310. The cubic root of 1720390725 is about 1198.2360019463.

The spelling of 1720390725 in words is "one billion, seven hundred twenty million, three hundred ninety thousand, seven hundred twenty-five".