100720 has 20 divisors (see below), whose sum is σ = 234360. Its totient is φ = 40256.

The previous prime is 100703. The next prime is 100733. The reversal of 100720 is 27001.

It is a tau number, because it is divible by the number of its divisors (20).

It is a Harshad number since it is a multiple of its sum of digits (10).

It is a junction number, because it is equal to n+sod(n) for n = 100697 and 100706.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 550 + ... + 709.

It is an arithmetic number, because the mean of its divisors is an integer number (11718).

2¹⁰⁰⁷²⁰ is an apocalyptic number.

100720 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

100720 is an abundant number, since it is smaller than the sum of its proper divisors (133640).

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

100720 is a wasteful number, since it uses less digits than its factorization.

100720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1272 (or 1266 counting only the distinct ones).

The product of its (nonzero) digits is 14, while the sum is 10.

The square root of 100720 is about 317.3641441625. The cubic root of 100720 is about 46.5270201769.

Adding to 100720 its reverse (27001), we get a palindrome (127721).

It can be divided in two parts, 100 and 720, that added together give a triangular number (820 = T₄₀).

The spelling of 100720 in words is "one hundred thousand, seven hundred twenty", and thus it is an iban number.