1720243155 has 16 divisors (see below), whose sum is σ = 2756288160. Its totient is φ = 916163328.

The previous prime is 1720243139. The next prime is 1720243169. The reversal of 1720243155 is 5513420271.

1720243155 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 1720243155 - 2⁴ = 1720243139 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 70242 + ... + 91511.

It is an arithmetic number, because the mean of its divisors is an integer number (172268010).

Almost surely, 2^1720243155 is an apocalyptic number.

1720243155 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1720243155 is a deficient number, since it is larger than the sum of its proper divisors (1036045005).

1720243155 is a wasteful number, since it uses less digits than its factorization.

1720243155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 162470.

The product of its (nonzero) digits is 8400, while the sum is 30.

The square root of 1720243155 is about 41475.8140968927. The cubic root of 1720243155 is about 1198.2017405931.

The spelling of 1720243155 in words is "one billion, seven hundred twenty million, two hundred forty-three thousand, one hundred fifty-five".