261378535 has 16 divisors (see below), whose sum is σ = 360178560. Its totient is φ = 180087840.

The previous prime is 261378529. The next prime is 261378581. The reversal of 261378535 is 535873162.

It is not a de Polignac number, because 261378535 - 2³ = 261378527 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 124017 + ... + 126106.

It is an arithmetic number, because the mean of its divisors is an integer number (22511160).

Almost surely, 2^261378535 is an apocalyptic number.

261378535 is a deficient number, since it is larger than the sum of its proper divisors (98800025).

261378535 is a wasteful number, since it uses less digits than its factorization.

261378535 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 250158.

The product of its digits is 151200, while the sum is 40.

The square root of 261378535 is about 16167.2055408472. The cubic root of 261378535 is about 639.3764556738.

The spelling of 261378535 in words is "two hundred sixty-one million, three hundred seventy-eight thousand, five hundred thirty-five".