55191971720 has 64 divisors (see below), whose sum is σ = 124695480240. Its totient is φ = 21985689600.

The previous prime is 55191971699. The next prime is 55191971729. The reversal of 55191971720 is 2717919155.

55191971720 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 8 ways, for example, as 3300042916 + 51891928804 = 57446^2 + 227798^2 .

It is not an unprimeable number, because it can be changed into a prime (55191971729) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10791884 + ... + 10796996.

Almost surely, 2^55191971720 is an apocalyptic number.

It is an amenable number.

55191971720 is an abundant number, since it is smaller than the sum of its proper divisors (69503508520).

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

55191971720 is a wasteful number, since it uses less digits than its factorization.

55191971720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6186 (or 6182 counting only the distinct ones).

The product of its (nonzero) digits is 198450, while the sum is 47.

The spelling of 55191971720 in words is "fifty-five billion, one hundred ninety-one million, nine hundred seventy-one thousand, seven hundred twenty".