261525945 has 32 divisors (see below), whose sum is σ = 429004800. Its totient is φ = 136004544.

The previous prime is 261525917. The next prime is 261525947. The reversal of 261525945 is 549525162.

261525945 = 178² + 179² + ... + 924².

It is not a de Polignac number, because 261525945 - 2¹² = 261521849 is a prime.

It is not an unprimeable number, because it can be changed into a prime (261525947) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 97026 + ... + 99684.

It is an arithmetic number, because the mean of its divisors is an integer number (13406400).

Almost surely, 2^261525945 is an apocalyptic number.

It is an amenable number.

261525945 is a deficient number, since it is larger than the sum of its proper divisors (167478855).

261525945 is a wasteful number, since it uses less digits than its factorization.

261525945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2829.

The product of its digits is 108000, while the sum is 39.

The square root of 261525945 is about 16171.7638184584. The cubic root of 261525945 is about 639.4966297484.

The spelling of 261525945 in words is "two hundred sixty-one million, five hundred twenty-five thousand, nine hundred forty-five".