512155721 has 16 divisors (see below), whose sum is σ = 639083520. Its totient is φ = 398737680.

The previous prime is 512155687. The next prime is 512155741. The reversal of 512155721 is 127551215.

It is not a de Polignac number, because 512155721 - 2¹⁴ = 512139337 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (512155741) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 121670 + ... + 125808.

It is an arithmetic number, because the mean of its divisors is an integer number (39942720).

Almost surely, 2^512155721 is an apocalyptic number.

It is an amenable number.

512155721 is a deficient number, since it is larger than the sum of its proper divisors (126927799).

512155721 is a wasteful number, since it uses less digits than its factorization.

512155721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5764.

The product of its digits is 3500, while the sum is 29.

The square root of 512155721 is about 22630.8577168432. The cubic root of 512155721 is about 800.0810964664.

The spelling of 512155721 in words is "five hundred twelve million, one hundred fifty-five thousand, seven hundred twenty-one".