123720537 has 4 divisors (see below), whose sum is σ = 164960720. Its totient is φ = 82480356.

The previous prime is 123720529. The next prime is 123720551. The reversal of 123720537 is 735027321.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 123720537 - 2³ = 123720529 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (123720937) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20620087 + ... + 20620092.

It is an arithmetic number, because the mean of its divisors is an integer number (41240180).

Almost surely, 2^123720537 is an apocalyptic number.

It is an amenable number.

123720537 is a deficient number, since it is larger than the sum of its proper divisors (41240183).

123720537 is an equidigital number, since it uses as much as digits as its factorization.

123720537 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41240182.

The product of its (nonzero) digits is 8820, while the sum is 30.

The square root of 123720537 is about 11122.9733884425. The cubic root of 123720537 is about 498.2881954719.

Adding to 123720537 its reverse (735027321), we get a palindrome (858747858).

The spelling of 123720537 in words is "one hundred twenty-three million, seven hundred twenty thousand, five hundred thirty-seven".