50391720918450 has 72 divisors (see below), whose sum is σ = 135976961324100. Its totient is φ = 13379111902080.

The previous prime is 50391720918439. The next prime is 50391720918479. The reversal of 50391720918450 is 5481902719305.

It is a happy number.

50391720918450 is a `hidden beast` number, since 5 + 0 + 3 + 9 + 172 + 0 + 9 + 18 + 450 = 666.

It can be written as a sum of positive squares in 6 ways, for example, as 45547394752161 + 4844326166289 = 6748881^2 + 2200983^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 244398265 + ... + 244604364.

Almost surely, 2^{50391720918450} is an apocalyptic number.

50391720918450 is a gapful number since it is divisible by the number (50) formed by its first and last digit.

50391720918450 is an abundant number, since it is smaller than the sum of its proper divisors (85585240405650).

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

50391720918450 is a wasteful number, since it uses less digits than its factorization.

50391720918450 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 489002876 (or 489002868 counting only the distinct ones).

The product of its (nonzero) digits is 2721600, while the sum is 54.

The spelling of 50391720918450 in words is "fifty trillion, three hundred ninety-one billion, seven hundred twenty million, nine hundred eighteen thousand, four hundred fifty".