51661111650 has 24 divisors (see below), whose sum is σ = 128119557264. Its totient is φ = 13776296400.

The previous prime is 51661111639. The next prime is 51661111651. The reversal of 51661111650 is 5611116615.

It is not an unprimeable number, because it can be changed into a prime (51661111651) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 172203556 + ... + 172203855.

It is an arithmetic number, because the mean of its divisors is an integer number (5338314886).

Almost surely, 2^51661111650 is an apocalyptic number.

51661111650 is a gapful number since it is divisible by the number (50) formed by its first and last digit.

51661111650 is an abundant number, since it is smaller than the sum of its proper divisors (76458445614).

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

51661111650 is a wasteful number, since it uses less digits than its factorization.

51661111650 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 344407426 (or 344407421 counting only the distinct ones).

The product of its (nonzero) digits is 5400, while the sum is 33.

The spelling of 51661111650 in words is "fifty-one billion, six hundred sixty-one million, one hundred eleven thousand, six hundred fifty".