2661254557 has 4 divisors (see below), whose sum is σ = 2865966460. Its totient is φ = 2456542656.

The previous prime is 2661254549. The next prime is 2661254573. The reversal of 2661254557 is 7554521662.

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 648924676 + 2012329881 = 25474^2 + 44859^2 .

It is a cyclic number.

It is not a de Polignac number, because 2661254557 - 2³ = 2661254549 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 (2661254587) 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, 102355932 + ... + 102355957.

It is an arithmetic number, because the mean of its divisors is an integer number (716491615).

Almost surely, 2^2661254557 is an apocalyptic number.

It is an amenable number.

2661254557 is a deficient number, since it is larger than the sum of its proper divisors (204711903).

2661254557 is a wasteful number, since it uses less digits than its factorization.

2661254557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 204711902.

The product of its digits is 504000, while the sum is 43.

The square root of 2661254557 is about 51587.3488076292. The cubic root of 2661254557 is about 1385.7837765084.

The spelling of 2661254557 in words is "two billion, six hundred sixty-one million, two hundred fifty-four thousand, five hundred fifty-seven".