1720172385 has 12 divisors (see below), whose sum is σ = 2981632212. Its totient is φ = 917425248.

The previous prime is 1720172359. The next prime is 1720172413. The reversal of 1720172385 is 5832710271.

1720172385 is a `hidden beast` number, since 1 + 7 + 201 + 72 + 385 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 579894561 + 1140277824 = 24081^2 + 33768^2 .

It is not a de Polignac number, because 1720172385 - 2⁷ = 1720172257 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 19112982 + ... + 19113071.

It is an arithmetic number, because the mean of its divisors is an integer number (248469351).

Almost surely, 2^1720172385 is an apocalyptic number.

1720172385 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1720172385 is a deficient number, since it is larger than the sum of its proper divisors (1261459827).

1720172385 is a wasteful number, since it uses less digits than its factorization.

1720172385 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38226064 (or 38226061 counting only the distinct ones).

The product of its (nonzero) digits is 23520, while the sum is 36.

The square root of 1720172385 is about 41474.9609403071. The cubic root of 1720172385 is about 1198.1853092145.

The spelling of 1720172385 in words is "one billion, seven hundred twenty million, one hundred seventy-two thousand, three hundred eighty-five".