1028491213 has 4 divisors (see below), whose sum is σ = 1028969308. Its totient is φ = 1028013120.

The previous prime is 1028491199. The next prime is 1028491231. The reversal of 1028491213 is 3121948201.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 285001924 + 743489289 = 16882^2 + 27267^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1028491213 is a prime.

It is a super-2 number, since 2×1028491213² = 2115588350436422738, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1028491813) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 235806 + ... + 240127.

It is an arithmetic number, because the mean of its divisors is an integer number (257242327).

Almost surely, 2^1028491213 is an apocalyptic number.

It is an amenable number.

1028491213 is a deficient number, since it is larger than the sum of its proper divisors (478095).

1028491213 is an equidigital number, since it uses as much as digits as its factorization.

1028491213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 478094.

The product of its (nonzero) digits is 3456, while the sum is 31.

The square root of 1028491213 is about 32070.0984251686. The cubic root of 1028491213 is about 1009.4082777170.

The spelling of 1028491213 in words is "one billion, twenty-eight million, four hundred ninety-one thousand, two hundred thirteen".