61686890934650 has 12 divisors (see below), whose sum is σ = 114737617138542. Its totient is φ = 24674756373840.

The previous prime is 61686890934637. The next prime is 61686890934659. The reversal of 61686890934650 is 5643909868616.

It can be written as a sum of positive squares in 3 ways, for example, as 30024470932681 + 31662420001969 = 5479459^2 + 5626937^2 .

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (61686890934659) 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, 616868909297 + ... + 616868909396.

Almost surely, 2^{61686890934650} is an apocalyptic number.

61686890934650 is a deficient number, since it is larger than the sum of its proper divisors (53050726203892).

61686890934650 is a wasteful number, since it uses less digits than its factorization.

61686890934650 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1233737818705 (or 1233737818700 counting only the distinct ones).

The product of its (nonzero) digits is 403107840, while the sum is 71.

The spelling of 61686890934650 in words is "sixty-one trillion, six hundred eighty-six billion, eight hundred ninety million, nine hundred thirty-four thousand, six hundred fifty".