2928061721 has 6 divisors (see below), whose sum is σ = 3170623230. Its totient is φ = 2702826048.

The previous prime is 2928061679. The next prime is 2928061733. The reversal of 2928061721 is 1271608292.

2928061721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 3 ways, for example, as 302934025 + 2625127696 = 17405^2 + 51236^2 .

It is not a de Polignac number, because 2928061721 - 2¹⁸ = 2927799577 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (2928061021) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 8662736 + ... + 8663073.

It is an arithmetic number, because the mean of its divisors is an integer number (528437205).

Almost surely, 2^2928061721 is an apocalyptic number.

It is an amenable number.

2928061721 is a deficient number, since it is larger than the sum of its proper divisors (242561509).

2928061721 is a wasteful number, since it uses less digits than its factorization.

2928061721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17325835 (or 17325822 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 38.

The square root of 2928061721 is about 54111.5673493201. The cubic root of 2928061721 is about 1430.6280712115.

The spelling of 2928061721 in words is "two billion, nine hundred twenty-eight million, sixty-one thousand, seven hundred twenty-one".