1004026561 has 4 divisors (see below), whose sum is σ = 1031162452. Its totient is φ = 976890672.

The previous prime is 1004026547. The next prime is 1004026589. The reversal of 1004026561 is 1656204001.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1656204001 = 47 ⋅35238383.

It can be written as a sum of positive squares in 2 ways, for example, as 480486400 + 523540161 = 21920^2 + 22881^2 .

It is a cyclic number.

It is not a de Polignac number, because 1004026561 - 2¹⁹ = 1003502273 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1004026501) 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, 13567890 + ... + 13567963.

It is an arithmetic number, because the mean of its divisors is an integer number (257790613).

Almost surely, 2^1004026561 is an apocalyptic number.

It is an amenable number.

1004026561 is a deficient number, since it is larger than the sum of its proper divisors (27135891).

1004026561 is an equidigital number, since it uses as much as digits as its factorization.

1004026561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27135890.

The product of its (nonzero) digits is 1440, while the sum is 25.

The square root of 1004026561 is about 31686.3781616012. The cubic root of 1004026561 is about 1001.3403895531.

The spelling of 1004026561 in words is "one billion, four million, twenty-six thousand, five hundred sixty-one".