61671265569 has 45 divisors (see below), whose sum is σ = 94568514249. Its totient is φ = 40051791360.

The previous prime is 61671265531. The next prime is 61671265603. The reversal of 61671265569 is 96556217616.

The square root of 61671265569 is 248337.

It is a perfect power (a square), and thus also a powerful number.

61671265569 is a `hidden beast` number, since 6 + 1 + 6 + 7 + 12 + 65 + 569 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 28067976225 + 33603289344 = 167535^2 + 183312^2 .

It is not a de Polignac number, because 61671265569 - 2²⁷ = 61537047841 is a prime.

It is a super-2 number, since 2×61671265569² (a number of 22 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

Its product of digits (4082400) is a multiple of the sum of its prime factors (1440).

It is not an unprimeable number, because it can be changed into a prime (61671265069) 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 44 ways as a sum of consecutive naturals, for example, 91636017 + ... + 91636689.

Almost surely, 2^61671265569 is an apocalyptic number.

61671265569 is the 248337-th square number.

61671265569 is the 124169-th centered octagonal number.

It is an amenable number.

61671265569 is a deficient number, since it is larger than the sum of its proper divisors (32897248680).

61671265569 is an frugal number, since it uses more digits than its factorization.

61671265569 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1440 (or 717 counting only the distinct ones).

The product of its digits is 4082400, while the sum is 54.

The spelling of 61671265569 in words is "sixty-one billion, six hundred seventy-one million, two hundred sixty-five thousand, five hundred sixty-nine".