2551205521 has 4 divisors (see below), whose sum is σ = 2701276452. Its totient is φ = 2401134592.

The previous prime is 2551205519. The next prime is 2551205549. The reversal of 2551205521 is 1255021552.

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 2188836225 + 362369296 = 46785^2 + 19036^2 .

It is a cyclic number.

It is not a de Polignac number, because 2551205521 - 2¹ = 2551205519 is a prime.

It is a super-2 number, since 2×2551205521² = 13017299220761762882, 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 2551205521.

It is not an unprimeable number, because it can be changed into a prime (2551205621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 75035440 + ... + 75035473.

It is an arithmetic number, because the mean of its divisors is an integer number (675319113).

Almost surely, 2^2551205521 is an apocalyptic number.

It is an amenable number.

2551205521 is a deficient number, since it is larger than the sum of its proper divisors (150070931).

2551205521 is a wasteful number, since it uses less digits than its factorization.

2551205521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 150070930.

The product of its (nonzero) digits is 5000, while the sum is 28.

The square root of 2551205521 is about 50509.4597179578. The cubic root of 2551205521 is about 1366.4124655576.

The spelling of 2551205521 in words is "two billion, five hundred fifty-one million, two hundred five thousand, five hundred twenty-one".