1720505020 has 24 divisors (see below), whose sum is σ = 3890988864. Its totient is φ = 635263296.

The previous prime is 1720504997. The next prime is 1720505029. The reversal of 1720505020 is 205050271.

It is a junction number, because it is equal to n+sod(n) for n = 1720504982 and 1720505000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1720505029) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3308404 + ... + 3308923.

It is an arithmetic number, because the mean of its divisors is an integer number (162124536).

Almost surely, 2^1720505020 is an apocalyptic number.

1720505020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1720505020 is an abundant number, since it is smaller than the sum of its proper divisors (2170483844).

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

1720505020 is a wasteful number, since it uses less digits than its factorization.

1720505020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6617349 (or 6617347 counting only the distinct ones).

The product of its (nonzero) digits is 700, while the sum is 22.

The square root of 1720505020 is about 41478.9708165475. The cubic root of 1720505020 is about 1198.2625364905.

Adding to 1720505020 its reverse (205050271), we get a palindrome (1925555291).

The spelling of 1720505020 in words is "one billion, seven hundred twenty million, five hundred five thousand, twenty".