2523240721 has 4 divisors (see below), whose sum is σ = 2523369712. Its totient is φ = 2523111732.

The previous prime is 2523240683. The next prime is 2523240761. The reversal of 2523240721 is 1270423252.

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 a cyclic number.

It is not a de Polignac number, because 2523240721 - 2⁷ = 2523240593 is a prime.

It is a super-2 number, since 2×2523240721² = 12733487472225199682, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2523240721.

It is not an unprimeable number, because it can be changed into a prime (2523240761) 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, 28431 + ... + 76516.

It is an arithmetic number, because the mean of its divisors is an integer number (630842428).

Almost surely, 2^2523240721 is an apocalyptic number.

It is an amenable number.

2523240721 is a deficient number, since it is larger than the sum of its proper divisors (128991).

2523240721 is a wasteful number, since it uses less digits than its factorization.

2523240721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128990.

The product of its (nonzero) digits is 6720, while the sum is 28.

The square root of 2523240721 is about 50231.8695750019. The cubic root of 2523240721 is about 1361.4015109891.

Adding to 2523240721 its reverse (1270423252), we get a palindrome (3793663973).

The spelling of 2523240721 in words is "two billion, five hundred twenty-three million, two hundred forty thousand, seven hundred twenty-one".