51161720620 has 12 divisors (see below), whose sum is σ = 107439613344. Its totient is φ = 20464688240.

The previous prime is 51161720593. The next prime is 51161720629. The reversal of 51161720620 is 2602716115.

It is not an unprimeable number, because it can be changed into a prime (51161720629) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1279042996 + ... + 1279043035.

It is an arithmetic number, because the mean of its divisors is an integer number (8953301112).

Almost surely, 2^51161720620 is an apocalyptic number.

It is an amenable number.

51161720620 is an abundant number, since it is smaller than the sum of its proper divisors (56277892724).

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

51161720620 is a wasteful number, since it uses less digits than its factorization.

51161720620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2558086040 (or 2558086038 counting only the distinct ones).

The product of its (nonzero) digits is 5040, while the sum is 31.

The spelling of 51161720620 in words is "fifty-one billion, one hundred sixty-one million, seven hundred twenty thousand, six hundred twenty".