61310051521 has 4 divisors (see below), whose sum is σ = 61319654100. Its totient is φ = 61300448944.

The previous prime is 61310051441. The next prime is 61310051531. The reversal of 61310051521 is 12515001316.

It is a happy number.

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 10007801521 + 51302250000 = 100039^2 + 226500^2 .

It is a cyclic number.

It is not a de Polignac number, because 61310051521 - 2⁹ = 61310051009 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61310051531) 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, 4791706 + ... + 4804483.

It is an arithmetic number, because the mean of its divisors is an integer number (15329913525).

Almost surely, 2^61310051521 is an apocalyptic number.

It is an amenable number.

61310051521 is a deficient number, since it is larger than the sum of its proper divisors (9602579).

61310051521 is an equidigital number, since it uses as much as digits as its factorization.

61310051521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9602578.

The product of its (nonzero) digits is 900, while the sum is 25.

Adding to 61310051521 its reverse (12515001316), we get a palindrome (73825052837).

The spelling of 61310051521 in words is "sixty-one billion, three hundred ten million, fifty-one thousand, five hundred twenty-one".