261349537 has 16 divisors (see below), whose sum is σ = 278839440. Its totient is φ = 244484352.

The previous prime is 261349523. The next prime is 261349547. The reversal of 261349537 is 735943162.

It is a happy number.

261349537 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 8 ways, for example, as 3779136 + 257570401 = 1944^2 + 16049^2 .

It is a cyclic number.

It is not a de Polignac number, because 261349537 - 2¹⁹ = 260825249 is a prime.

It is a super-2 number, since 2×261349537² = 136607160980228738, which contains 22 as substring.

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 261349537.

It is not an unprimeable number, because it can be changed into a prime (261349547) 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, 399903 + ... + 400555.

It is an arithmetic number, because the mean of its divisors is an integer number (17427465).

Almost surely, 2^261349537 is an apocalyptic number.

It is an amenable number.

261349537 is a deficient number, since it is larger than the sum of its proper divisors (17489903).

261349537 is a wasteful number, since it uses less digits than its factorization.

261349537 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1092.

The product of its digits is 136080, while the sum is 40.

The square root of 261349537 is about 16166.3087005043. The cubic root of 261349537 is about 639.3528101155.

The spelling of 261349537 in words is "two hundred sixty-one million, three hundred forty-nine thousand, five hundred thirty-seven".