1042217581 has 4 divisors (see below), whose sum is σ = 1067637564. Its totient is φ = 1016797600.

The previous prime is 1042217549. The next prime is 1042217587. The reversal of 1042217581 is 1857122401.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1857122401 = 277 ⋅6704413.

It can be written as a sum of positive squares in 2 ways, for example, as 486908356 + 555309225 = 22066^2 + 23565^2 .

It is a cyclic number.

It is not a de Polignac number, because 1042217581 - 2⁵ = 1042217549 is a prime.

It is a super-2 number, since 2×1042217581² = 2172434972290983122, 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 (1042217587) 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, 12709930 + ... + 12710011.

It is an arithmetic number, because the mean of its divisors is an integer number (266909391).

Almost surely, 2^1042217581 is an apocalyptic number.

It is an amenable number.

1042217581 is a deficient number, since it is larger than the sum of its proper divisors (25419983).

1042217581 is an equidigital number, since it uses as much as digits as its factorization.

1042217581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25419982.

The product of its (nonzero) digits is 4480, while the sum is 31.

The square root of 1042217581 is about 32283.3948183892. The cubic root of 1042217581 is about 1013.8790089537.

Adding to 1042217581 its reverse (1857122401), we get a palindrome (2899339982).

The spelling of 1042217581 in words is "one billion, forty-two million, two hundred seventeen thousand, five hundred eighty-one".