261099607 has 4 divisors (see below), whose sum is σ = 261138376. Its totient is φ = 261060840.

The previous prime is 261099599. The next prime is 261099649. The reversal of 261099607 is 706990162.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 706990162 = 2 ⋅353495081.

It is a cyclic number.

It is not a de Polignac number, because 261099607 - 2³ = 261099599 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 261099607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261099667) 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, 6369 + ... + 23722.

It is an arithmetic number, because the mean of its divisors is an integer number (65284594).

Almost surely, 2^261099607 is an apocalyptic number.

261099607 is a deficient number, since it is larger than the sum of its proper divisors (38769).

261099607 is an equidigital number, since it uses as much as digits as its factorization.

261099607 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38768.

The product of its (nonzero) digits is 40824, while the sum is 40.

The square root of 261099607 is about 16158.5768865949. The cubic root of 261099607 is about 639.1489395777.

The spelling of 261099607 in words is "two hundred sixty-one million, ninety-nine thousand, six hundred seven".