53123721 has 16 divisors (see below), whose sum is σ = 84470784. Its totient is φ = 29036304.

The previous prime is 53123713. The next prime is 53123723. The reversal of 53123721 is 12732135.

It is not a de Polignac number, because 53123721 - 2³ = 53123713 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 53123691 and 53123700.

It is not an unprimeable number, because it can be changed into a prime (53123723) 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, 54511 + ... + 55476.

It is an arithmetic number, because the mean of its divisors is an integer number (5279424).

Almost surely, 2^53123721 is an apocalyptic number.

It is an amenable number.

53123721 is a deficient number, since it is larger than the sum of its proper divisors (31347063).

53123721 is a wasteful number, since it uses less digits than its factorization.

53123721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 110020.

The product of its digits is 1260, while the sum is 24.

The square root of 53123721 is about 7288.6021293524. The cubic root of 53123721 is about 375.9206322029.

Adding to 53123721 its reverse (12732135), we get a palindrome (65855856).

The spelling of 53123721 in words is "fifty-three million, one hundred twenty-three thousand, seven hundred twenty-one".