2533243721 has 4 divisors (see below), whose sum is σ = 2558325444. Its totient is φ = 2508162000.

The previous prime is 2533243693. The next prime is 2533243733. The reversal of 2533243721 is 1273423352.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 2375490121 + 157753600 = 48739^2 + 12560^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2533243721 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (2533243751) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12540710 + ... + 12540911.

It is an arithmetic number, because the mean of its divisors is an integer number (639581361).

Almost surely, 2^2533243721 is an apocalyptic number.

It is an amenable number.

2533243721 is a deficient number, since it is larger than the sum of its proper divisors (25081723).

2533243721 is a wasteful number, since it uses less digits than its factorization.

2533243721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25081722.

The product of its digits is 30240, while the sum is 32.

The square root of 2533243721 is about 50331.3393523359. The cubic root of 2533243721 is about 1363.1981612400.

The spelling of 2533243721 in words is "two billion, five hundred thirty-three million, two hundred forty-three thousand, seven hundred twenty-one".