261606503 has 4 divisors (see below), whose sum is σ = 261806160. Its totient is φ = 261406848.

The previous prime is 261606493. The next prime is 261606517. The reversal of 261606503 is 305606162.

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 261606503 - 2⁴ = 261606487 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 (261606533) 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, 97850 + ... + 100487.

It is an arithmetic number, because the mean of its divisors is an integer number (65451540).

Almost surely, 2^261606503 is an apocalyptic number.

261606503 is a deficient number, since it is larger than the sum of its proper divisors (199657).

261606503 is a wasteful number, since it uses less digits than its factorization.

261606503 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 199656.

The product of its (nonzero) digits is 6480, while the sum is 29.

The square root of 261606503 is about 16174.2543259342. The cubic root of 261606503 is about 639.5622845229.

The spelling of 261606503 in words is "two hundred sixty-one million, six hundred six thousand, five hundred three".