261775749 has 16 divisors (see below), whose sum is σ = 379258880. Its totient is φ = 159997680.

The previous prime is 261775727. The next prime is 261775751. The reversal of 261775749 is 947577162.

It is a happy number.

261775749 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 261775749 - 2⁹ = 261775237 is a prime.

It is a super-2 number, since 2×261775749² = 137053085529022002, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 261775698 and 261775707.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261775769) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 72307 + ... + 75840.

It is an arithmetic number, because the mean of its divisors is an integer number (23703680).

Almost surely, 2^261775749 is an apocalyptic number.

It is an amenable number.

261775749 is a deficient number, since it is larger than the sum of its proper divisors (117483131).

261775749 is a wasteful number, since it uses less digits than its factorization.

261775749 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 148200.

The product of its digits is 740880, while the sum is 48.

The square root of 261775749 is about 16179.4854368116. The cubic root of 261775749 is about 639.7001761310.

The spelling of 261775749 in words is "two hundred sixty-one million, seven hundred seventy-five thousand, seven hundred forty-nine".