261617893 has 4 divisors (see below), whose sum is σ = 272992608. Its totient is φ = 250243180.

The previous prime is 261617789. The next prime is 261617929. The reversal of 261617893 is 398716162.

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.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-261617893 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261617393) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5687323 + ... + 5687368.

It is an arithmetic number, because the mean of its divisors is an integer number (68248152).

Almost surely, 2^261617893 is an apocalyptic number.

261617893 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

It is an amenable number.

261617893 is a deficient number, since it is larger than the sum of its proper divisors (11374715).

261617893 is a wasteful number, since it uses less digits than its factorization.

261617893 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11374714.

The product of its digits is 108864, while the sum is 43.

The square root of 261617893 is about 16174.6064248871. The cubic root of 261617893 is about 639.5715662860.

The spelling of 261617893 in words is "two hundred sixty-one million, six hundred seventeen thousand, eight hundred ninety-three".