5155505721 has 12 divisors (see below), whose sum is σ = 7456485348. Its totient is φ = 3432552864.

The previous prime is 5155505713. The next prime is 5155505723. The reversal of 5155505721 is 1275055515.

5155505721 is a `hidden beast` number, since 51 + 5 + 550 + 57 + 2 + 1 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 2048558121 + 3106947600 = 45261^2 + 55740^2 .

It is not a de Polignac number, because 5155505721 - 2³ = 5155505713 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (5155505723) 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, 363570 + ... + 377483.

It is an arithmetic number, because the mean of its divisors is an integer number (621373779).

Almost surely, 2^5155505721 is an apocalyptic number.

It is an amenable number.

5155505721 is a deficient number, since it is larger than the sum of its proper divisors (2300979627).

5155505721 is a wasteful number, since it uses less digits than its factorization.

5155505721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 741832 (or 741829 counting only the distinct ones).

The product of its (nonzero) digits is 43750, while the sum is 36.

The square root of 5155505721 is about 71801.8504009472. The cubic root of 5155505721 is about 1727.5226797391.

The spelling of 5155505721 in words is "five billion, one hundred fifty-five million, five hundred five thousand, seven hundred twenty-one".