61545128719 has 4 divisors (see below), whose sum is σ = 64784346040. Its totient is φ = 58305911400.

The previous prime is 61545128717. The next prime is 61545128819. The reversal of 61545128719 is 91782154516.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 61545128719 - 2¹ = 61545128717 is a prime.

It is a super-2 number, since 2×61545128719² (a number of 22 digits) contains 22 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 (61545128717) 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, 1619608632 + ... + 1619608669.

It is an arithmetic number, because the mean of its divisors is an integer number (16196086510).

Almost surely, 2^61545128719 is an apocalyptic number.

61545128719 is a deficient number, since it is larger than the sum of its proper divisors (3239217321).

61545128719 is a wasteful number, since it uses less digits than its factorization.

61545128719 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3239217320.

The product of its digits is 604800, while the sum is 49.

The spelling of 61545128719 in words is "sixty-one billion, five hundred forty-five million, one hundred twenty-eight thousand, seven hundred nineteen".