261290851 has 4 divisors (see below), whose sum is σ = 261471400. Its totient is φ = 261110304.

The previous prime is 261290849. The next prime is 261290857. The reversal of 261290851 is 158092162.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 261290851 - 2¹ = 261290849 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261290857) 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, 88086 + ... + 91003.

It is an arithmetic number, because the mean of its divisors is an integer number (65367850).

Almost surely, 2^261290851 is an apocalyptic number.

261290851 is a deficient number, since it is larger than the sum of its proper divisors (180549).

261290851 is a wasteful number, since it uses less digits than its factorization.

261290851 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 180548.

The product of its (nonzero) digits is 8640, while the sum is 34.

The square root of 261290851 is about 16164.4935274818. The cubic root of 261290851 is about 639.3049510067.

The spelling of 261290851 in words is "two hundred sixty-one million, two hundred ninety thousand, eight hundred fifty-one".