915006721 has 4 divisors (see below), whose sum is σ = 915595200. Its totient is φ = 914418244.

The previous prime is 915006689. The next prime is 915006727. The reversal of 915006721 is 127600519.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 127600519 = 1013 ⋅125963.

It is a cyclic number.

It is not a de Polignac number, because 915006721 - 2⁵ = 915006689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (915006727) 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 3 ways as a sum of consecutive naturals, for example, 291901 + ... + 295018.

It is an arithmetic number, because the mean of its divisors is an integer number (228898800).

Almost surely, 2^915006721 is an apocalyptic number.

It is an amenable number.

915006721 is a deficient number, since it is larger than the sum of its proper divisors (588479).

915006721 is a wasteful number, since it uses less digits than its factorization.

915006721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 588478.

The product of its (nonzero) digits is 3780, while the sum is 31.

The square root of 915006721 is about 30249.0780190075. The cubic root of 915006721 is about 970.8260653626.

The spelling of 915006721 in words is "nine hundred fifteen million, six thousand, seven hundred twenty-one".