261405016 has 8 divisors (see below), whose sum is σ = 490134420. Its totient is φ = 130702504.

The previous prime is 261404993. The next prime is 261405049. The reversal of 261405016 is 610504162.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 16337806 + ... + 16337821.

Almost surely, 2^261405016 is an apocalyptic number.

It is an amenable number.

261405016 is a deficient number, since it is larger than the sum of its proper divisors (228729404).

261405016 is a wasteful number, since it uses less digits than its factorization.

261405016 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32675633 (or 32675629 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 25.

The square root of 261405016 is about 16168.0244928068. The cubic root of 261405016 is about 639.3980472915.

Adding to 261405016 its reverse (610504162), we get a palindrome (871909178).

The spelling of 261405016 in words is "two hundred sixty-one million, four hundred five thousand, sixteen".