261099603 has 48 divisors (see below), whose sum is σ = 400982400. Its totient is φ = 163532160.

The previous prime is 261099599. The next prime is 261099649. The reversal of 261099603 is 306990162.

It is not a de Polignac number, because 261099603 - 2² = 261099599 is a prime.

It is not an unprimeable number, because it can be changed into a prime (261099403) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1458568 + ... + 1458746.

It is an arithmetic number, because the mean of its divisors is an integer number (8353800).

Almost surely, 2^261099603 is an apocalyptic number.

261099603 is a deficient number, since it is larger than the sum of its proper divisors (139882797).

261099603 is a wasteful number, since it uses less digits than its factorization.

261099603 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 352 (or 349 counting only the distinct ones).

The product of its (nonzero) digits is 17496, while the sum is 36.

The square root of 261099603 is about 16158.5767628217. The cubic root of 261099603 is about 639.1489363138.

The spelling of 261099603 in words is "two hundred sixty-one million, ninety-nine thousand, six hundred three".