261892993 has 4 divisors (see below), whose sum is σ = 268971220. Its totient is φ = 254814768.

The previous prime is 261892987. The next prime is 261892999. The reversal of 261892993 is 399298162.

261892993 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.

It is an interprime number because it is at equal distance from previous prime (261892987) and next prime (261892999).

It can be written as a sum of positive squares in 2 ways, for example, as 250683889 + 11209104 = 15833^2 + 3348^2 .

It is a cyclic number.

It is not a de Polignac number, because 261892993 - 2¹³ = 261884801 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261892999) 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, 3539058 + ... + 3539131.

It is an arithmetic number, because the mean of its divisors is an integer number (67242805).

Almost surely, 2^261892993 is an apocalyptic number.

It is an amenable number.

261892993 is a deficient number, since it is larger than the sum of its proper divisors (7078227).

261892993 is an equidigital number, since it uses as much as digits as its factorization.

261892993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7078226.

The product of its digits is 419904, while the sum is 49.

The square root of 261892993 is about 16183.1082613940. The cubic root of 261892993 is about 639.7956647485.

The spelling of 261892993 in words is "two hundred sixty-one million, eight hundred ninety-two thousand, nine hundred ninety-three".