61312533138 has 24 divisors (see below), whose sum is σ = 133611711948. Its totient is φ = 20319374112.

The previous prime is 61312533133. The next prime is 61312533209. The reversal of 61312533138 is 83133521316.

61312533138 is a `hidden beast` number, since 6 + 1 + 312 + 5 + 331 + 3 + 8 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 60857436249 + 455096889 = 246693^2 + 21333^2 .

It is not an unprimeable number, because it can be changed into a prime (61312533131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9841545 + ... + 9847772.

Almost surely, 2^61312533138 is an apocalyptic number.

61312533138 is an abundant number, since it is smaller than the sum of its proper divisors (72299178810).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

61312533138 is a wasteful number, since it uses less digits than its factorization.

61312533138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19689498 (or 19689495 counting only the distinct ones).

The product of its digits is 38880, while the sum is 36.

The spelling of 61312533138 in words is "sixty-one billion, three hundred twelve million, five hundred thirty-three thousand, one hundred thirty-eight".