261512 has 16 divisors (see below), whose sum is σ = 496860. Its totient is φ = 129024.

The previous prime is 261509. The next prime is 261523. The reversal of 261512 is 215162.

261512 = 49² + 50² + ... + 96².

It can be written as a sum of positive squares in 2 ways, for example, as 256036 + 5476 = 506^2 + 74^2 .

It is a super-2 number, since 2×261512² = 136777052288, which contains 22 as substring.

It is a nialpdrome in base 8.

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 608 + ... + 944.

2²⁶¹⁵¹² is an apocalyptic number.

It is an amenable number.

261512 is a deficient number, since it is larger than the sum of its proper divisors (235348).

261512 is a wasteful number, since it uses less digits than its factorization.

261512 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 440 (or 436 counting only the distinct ones).

The product of its digits is 120, while the sum is 17.

The square root of 261512 is about 511.3824400583. The cubic root of 261512 is about 63.9485263204.

Adding to 261512 its reverse (215162), we get a palindrome (476674).

The spelling of 261512 in words is "two hundred sixty-one thousand, five hundred twelve".