1720720131 has 16 divisors (see below), whose sum is σ = 2550481920. Its totient is φ = 1024745760.
The previous prime is 1720720097. The next prime is 1720720159. The reversal of 1720720131 is 1310270271.
It is not a de Polignac number, because 1720720131 - 222 = 1716525827 is a prime.
It is a super-2 number, since 2×17207201312 = 5921755538457314322, which contains 22 as substring.
It is not an unprimeable number, because it can be changed into a prime (1720720171) by changing a digit.
It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 710421 + ... + 712838.
It is an arithmetic number, because the mean of its divisors is an integer number (159405120).
Almost surely, 21720720131 is an apocalyptic number.
1720720131 is a deficient number, since it is larger than the sum of its proper divisors (829761789).
1720720131 is a wasteful number, since it uses less digits than its factorization.
1720720131 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 1423306.
The product of its (nonzero) digits is 588, while the sum is 24.
The square root of 1720720131 is about 41481.5637482485. The cubic root of 1720720131 is about 1198.3124731289.
The spelling of 1720720131 in words is "one billion, seven hundred twenty million, seven hundred twenty thousand, one hundred thirty-one".
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