245500661521 has 4 divisors (see below), whose sum is σ = 245692910772. Its totient is φ = 245308412272.

The previous prime is 245500661513. The next prime is 245500661563. The reversal of 245500661521 is 125166005542.

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 65364080896 + 180136580625 = 255664^2 + 424425^2 .

It is a cyclic number.

It is not a de Polignac number, because 245500661521 - 2³ = 245500661513 is a prime.

It is a super-2 number, since 2×245500661521² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (245500661591) 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, 96122710 + ... + 96125263.

It is an arithmetic number, because the mean of its divisors is an integer number (61423227693).

Almost surely, 2^245500661521 is an apocalyptic number.

It is an amenable number.

245500661521 is a deficient number, since it is larger than the sum of its proper divisors (192249251).

245500661521 is a wasteful number, since it uses less digits than its factorization.

245500661521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 192249250.

The product of its (nonzero) digits is 72000, while the sum is 37.

The spelling of 245500661521 in words is "two hundred forty-five billion, five hundred million, six hundred sixty-one thousand, five hundred twenty-one".