61281667181 has 6 divisors (see below), whose sum is σ = 71286837390. Its totient is φ = 52527143256.

The previous prime is 61281667171. The next prime is 61281667211. The reversal of 61281667181 is 18176618216.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 51454117225 + 9827549956 = 226835^2 + 99134^2 .

It is not a de Polignac number, because 61281667181 - 2¹⁰ = 61281666157 is a prime.

It is a super-2 number, since 2×61281667181² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61281667121) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 625323086 + ... + 625323183.

It is an arithmetic number, because the mean of its divisors is an integer number (11881139565).

Almost surely, 2^61281667181 is an apocalyptic number.

It is an amenable number.

61281667181 is a deficient number, since it is larger than the sum of its proper divisors (10005170209).

61281667181 is a wasteful number, since it uses less digits than its factorization.

61281667181 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1250646283 (or 1250646276 counting only the distinct ones).

The product of its digits is 193536, while the sum is 47.

The spelling of 61281667181 in words is "sixty-one billion, two hundred eighty-one million, six hundred sixty-seven thousand, one hundred eighty-one".