1720161540 has 36 divisors (see below), whose sum is σ = 5217823884. Its totient is φ = 458709696.

The previous prime is 1720161529. The next prime is 1720161571. The reversal of 1720161540 is 451610271.

It is a happy number.

1720161540 is a `hidden beast` number, since 1 + 7 + 2 + 0 + 1 + 615 + 40 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 1240025796 + 480135744 = 35214^2 + 21912^2 .

It is a tau number, because it is divible by the number of its divisors (36).

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 11 ways as a sum of consecutive naturals, for example, 4778047 + ... + 4778406.

Almost surely, 2^1720161540 is an apocalyptic number.

1720161540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1720161540 is an abundant number, since it is smaller than the sum of its proper divisors (3497662344).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1720161540 is a wasteful number, since it uses less digits than its factorization.

1720161540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9556468 (or 9556463 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 27.

The square root of 1720161540 is about 41474.8301985674. The cubic root of 1720161540 is about 1198.1827911825.

The spelling of 1720161540 in words is "one billion, seven hundred twenty million, one hundred sixty-one thousand, five hundred forty".