61144780877 has 8 divisors (see below), whose sum is σ = 62160889752. Its totient is φ = 60129115200.

The previous prime is 61144780867. The next prime is 61144780891. The reversal of 61144780877 is 77808744116.

It can be written as a sum of positive squares in 4 ways, for example, as 138744841 + 61006036036 = 11779^2 + 246994^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 61144780877 - 2⁴ = 61144780861 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61144780867) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 173423 + ... + 390339.

It is an arithmetic number, because the mean of its divisors is an integer number (7770111219).

Almost surely, 2^61144780877 is an apocalyptic number.

It is an amenable number.

61144780877 is a deficient number, since it is larger than the sum of its proper divisors (1016108875).

61144780877 is a wasteful number, since it uses less digits than its factorization.

61144780877 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 221599.

The product of its (nonzero) digits is 2107392, while the sum is 53.

The spelling of 61144780877 in words is "sixty-one billion, one hundred forty-four million, seven hundred eighty thousand, eight hundred seventy-seven".