1305016721 has 8 divisors (see below), whose sum is σ = 1346474880. Its totient is φ = 1264182192.

The previous prime is 1305016717. The next prime is 1305016753. The reversal of 1305016721 is 1276105031.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1305016721 - 2² = 1305016717 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1305016771) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 151655 + ... + 160028.

It is an arithmetic number, because the mean of its divisors is an integer number (168309360).

Almost surely, 2^1305016721 is an apocalyptic number.

It is an amenable number.

1305016721 is a deficient number, since it is larger than the sum of its proper divisors (41458159).

1305016721 is an equidigital number, since it uses as much as digits as its factorization.

1305016721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 311815.

The product of its (nonzero) digits is 1260, while the sum is 26.

The square root of 1305016721 is about 36125.0151695470. The cubic root of 1305016721 is about 1092.7949819527.

The spelling of 1305016721 in words is "one billion, three hundred five million, sixteen thousand, seven hundred twenty-one".