1288204721 has 8 divisors (see below), whose sum is σ = 1330178304. Its totient is φ = 1246257360.

The previous prime is 1288204711. The next prime is 1288204727. The reversal of 1288204721 is 1274028821.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1288204721 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1288204727) 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, 164726 + ... + 172368.

It is an arithmetic number, because the mean of its divisors is an integer number (166272288).

Almost surely, 2^1288204721 is an apocalyptic number.

It is an amenable number.

1288204721 is a deficient number, since it is larger than the sum of its proper divisors (41973583).

1288204721 is an equidigital number, since it uses as much as digits as its factorization.

1288204721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13111.

The product of its (nonzero) digits is 14336, while the sum is 35.

The square root of 1288204721 is about 35891.5689403514. The cubic root of 1288204721 is about 1088.0820073283.

The spelling of 1288204721 in words is "one billion, two hundred eighty-eight million, two hundred four thousand, seven hundred twenty-one".