1028952721 has 6 divisors (see below), whose sum is σ = 1057515270. Its totient is φ = 1001141856.

The previous prime is 1028952709. The next prime is 1028952773. The reversal of 1028952721 is 1272598201.

It is the 13096-th star number.

It can be written as a sum of positive squares in 3 ways, for example, as 435348225 + 593604496 = 20865^2 + 24364^2 .

It is not a de Polignac number, because 1028952721 - 2⁵ = 1028952689 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (37).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1028952791) 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, 374436 + ... + 377173.

It is an arithmetic number, because the mean of its divisors is an integer number (176252545).

Almost surely, 2^1028952721 is an apocalyptic number.

It is an amenable number.

1028952721 is a deficient number, since it is larger than the sum of its proper divisors (28562549).

1028952721 is an frugal number, since it uses more digits than its factorization.

1028952721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 751683 (or 751646 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 37.

The square root of 1028952721 is about 32077.2929188234. The cubic root of 1028952721 is about 1009.5592368202.

The spelling of 1028952721 in words is "one billion, twenty-eight million, nine hundred fifty-two thousand, seven hundred twenty-one".