2657642221 has 4 divisors (see below), whose sum is σ = 2862076252. Its totient is φ = 2453208192.

The previous prime is 2657642173. The next prime is 2657642227. The reversal of 2657642221 is 1222467562.

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 1398386025 + 1259256196 = 37395^2 + 35486^2 .

It is a cyclic number.

It is not a de Polignac number, because 2657642221 - 2⁹ = 2657641709 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 (2657642227) 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, 102216996 + ... + 102217021.

It is an arithmetic number, because the mean of its divisors is an integer number (715519063).

Almost surely, 2^2657642221 is an apocalyptic number.

It is an amenable number.

2657642221 is a deficient number, since it is larger than the sum of its proper divisors (204434031).

2657642221 is a wasteful number, since it uses less digits than its factorization.

2657642221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 204434030.

The product of its digits is 80640, while the sum is 37.

The square root of 2657642221 is about 51552.3250785064. The cubic root of 2657642221 is about 1385.1564804713.

The spelling of 2657642221 in words is "two billion, six hundred fifty-seven million, six hundred forty-two thousand, two hundred twenty-one".