61128587497 has 4 divisors (see below), whose sum is σ = 61165480276. Its totient is φ = 61091694720.

The previous prime is 61128587449. The next prime is 61128587557. The reversal of 61128587497 is 79478582116.

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 44837639001 + 16290948496 = 211749^2 + 127636^2 .

It is a cyclic number.

It is not a de Polignac number, because 61128587497 - 2¹⁹ = 61128063209 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61128582497) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18443904 + ... + 18447217.

It is an arithmetic number, because the mean of its divisors is an integer number (15291370069).

Almost surely, 2^61128587497 is an apocalyptic number.

It is an amenable number.

61128587497 is a deficient number, since it is larger than the sum of its proper divisors (36892779).

61128587497 is a wasteful number, since it uses less digits than its factorization.

61128587497 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36892778.

The product of its digits is 6773760, while the sum is 58.

The spelling of 61128587497 in words is "sixty-one billion, one hundred twenty-eight million, five hundred eighty-seven thousand, four hundred ninety-seven".