261765998 has 16 divisors (see below), whose sum is σ = 423402336. Its totient is φ = 120658080.

The previous prime is 261765991. The next prime is 261766033. The reversal of 261765998 is 899567162.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261765991) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15215 + ... + 27477.

It is an arithmetic number, because the mean of its divisors is an integer number (26462646).

Almost surely, 2^261765998 is an apocalyptic number.

261765998 is a deficient number, since it is larger than the sum of its proper divisors (161636338).

261765998 is a wasteful number, since it uses less digits than its factorization.

261765998 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13099.

The product of its digits is 1632960, while the sum is 53.

The square root of 261765998 is about 16179.1840956211. The cubic root of 261765998 is about 639.6922332080.

The spelling of 261765998 in words is "two hundred sixty-one million, seven hundred sixty-five thousand, nine hundred ninety-eight".