2544660021 has 4 divisors (see below), whose sum is σ = 3392880032. Its totient is φ = 1696440012.

The previous prime is 2544659969. The next prime is 2544660023. The reversal of 2544660021 is 1200664452.

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 2544660021 - 2¹³ = 2544651829 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2544660023) 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, 424110001 + ... + 424110006.

It is an arithmetic number, because the mean of its divisors is an integer number (848220008).

Almost surely, 2^2544660021 is an apocalyptic number.

It is an amenable number.

2544660021 is a deficient number, since it is larger than the sum of its proper divisors (848220011).

2544660021 is an equidigital number, since it uses as much as digits as its factorization.

2544660021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 848220010.

The product of its (nonzero) digits is 11520, while the sum is 30.

The square root of 2544660021 is about 50444.6233111122. The cubic root of 2544660021 is about 1365.2428861082.

The spelling of 2544660021 in words is "two billion, five hundred forty-four million, six hundred sixty thousand, twenty-one".