261500051 has 4 divisors (see below), whose sum is σ = 261886992. Its totient is φ = 261113112.

The previous prime is 261500027. The next prime is 261500077. The reversal of 261500051 is 150005162.

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 261500051 - 2¹⁰ = 261499027 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 261499996 and 261500032.

It is not an unprimeable number, because it can be changed into a prime (261500081) 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, 192455 + ... + 193808.

It is an arithmetic number, because the mean of its divisors is an integer number (65471748).

Almost surely, 2^261500051 is an apocalyptic number.

261500051 is a deficient number, since it is larger than the sum of its proper divisors (386941).

261500051 is an equidigital number, since it uses as much as digits as its factorization.

261500051 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 386940.

The product of its (nonzero) digits is 300, while the sum is 20.

The square root of 261500051 is about 16170.9632056968. The cubic root of 261500051 is about 639.4755232737.

The spelling of 261500051 in words is "two hundred sixty-one million, five hundred thousand, fifty-one".