1028011561 has 4 divisors (see below), whose sum is σ = 1029891472. Its totient is φ = 1026131652.

The previous prime is 1028011559. The next prime is 1028011597. The reversal of 1028011561 is 1651108201.

It is a happy number.

1028011561 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1651108201 = 113 ⋅14611577.

It is a cyclic number.

It is not a de Polignac number, because 1028011561 - 2¹ = 1028011559 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1028011861) 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, 939135 + ... + 940228.

It is an arithmetic number, because the mean of its divisors is an integer number (257472868).

Almost surely, 2^1028011561 is an apocalyptic number.

It is an amenable number.

1028011561 is a deficient number, since it is larger than the sum of its proper divisors (1879911).

1028011561 is an equidigital number, since it uses as much as digits as its factorization.

1028011561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1879910.

The product of its (nonzero) digits is 480, while the sum is 25.

The square root of 1028011561 is about 32062.6193720975. The cubic root of 1028011561 is about 1009.2513358529.

Adding to 1028011561 its reverse (1651108201), we get a palindrome (2679119762).

The spelling of 1028011561 in words is "one billion, twenty-eight million, eleven thousand, five hundred sixty-one".