61178445557 has 4 divisors (see below), whose sum is σ = 62181370956. Its totient is φ = 60175520160.

The previous prime is 61178445551. The next prime is 61178445593. The reversal of 61178445557 is 75554487116.

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 602898916 + 60575546641 = 24554^2 + 246121^2 .

It is a cyclic number.

It is not a de Polignac number, because 61178445557 - 2⁴ = 61178445541 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 61178445499 and 61178445508.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61178445551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 501462608 + ... + 501462729.

It is an arithmetic number, because the mean of its divisors is an integer number (15545342739).

Almost surely, 2^61178445557 is an apocalyptic number.

It is an amenable number.

61178445557 is a deficient number, since it is larger than the sum of its proper divisors (1002925399).

61178445557 is a wasteful number, since it uses less digits than its factorization.

61178445557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1002925398.

The product of its digits is 4704000, while the sum is 53.

The spelling of 61178445557 in words is "sixty-one billion, one hundred seventy-eight million, four hundred forty-five thousand, five hundred fifty-seven".