123720731 has 2 divisors, whose sum is σ = 123720732. Its totient is φ = 123720730.

The previous prime is 123720719. The next prime is 123720797. The reversal of 123720731 is 137027321.

It is a weak prime.

It is an emirp because it is prime and its reverse (137027321) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 123720731 - 2¹⁰ = 123719707 is a prime.

It is a super-2 number, since 2×123720731² = 30613638558348722, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 123720731.

It is not a weakly prime, because it can be changed into another prime (123720131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61860365 + 61860366.

It is an arithmetic number, because the mean of its divisors is an integer number (61860366).

Almost surely, 2^123720731 is an apocalyptic number.

123720731 is a deficient number, since it is larger than the sum of its proper divisors (1).

123720731 is an equidigital number, since it uses as much as digits as its factorization.

123720731 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1764, while the sum is 26.

The square root of 123720731 is about 11122.9821091288. The cubic root of 123720731 is about 498.2884559187.

The spelling of 123720731 in words is "one hundred twenty-three million, seven hundred twenty thousand, seven hundred thirty-one".