61661313053 has 4 divisors (see below), whose sum is σ = 62824734108. Its totient is φ = 60497892000.

The previous prime is 61661313047. The next prime is 61661313083. The reversal of 61661313053 is 35031316616.

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 47675412409 + 13985900644 = 218347^2 + 118262^2 .

It is a cyclic number.

It is not a de Polignac number, because 61661313053 - 2¹⁶ = 61661247517 is a prime.

It is a super-3 number, since 3×61661313053³ (a number of 33 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61661313083) 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, 581710448 + ... + 581710553.

It is an arithmetic number, because the mean of its divisors is an integer number (15706183527).

Almost surely, 2^61661313053 is an apocalyptic number.

It is an amenable number.

61661313053 is a deficient number, since it is larger than the sum of its proper divisors (1163421055).

61661313053 is a wasteful number, since it uses less digits than its factorization.

61661313053 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1163421054.

The product of its (nonzero) digits is 29160, while the sum is 35.

Adding to 61661313053 its reverse (35031316616), we get a palindrome (96692629669).

The spelling of 61661313053 in words is "sixty-one billion, six hundred sixty-one million, three hundred thirteen thousand, fifty-three".