261225645 has 16 divisors (see below), whose sum is σ = 427682112. Its totient is φ = 136080000.

The previous prime is 261225641. The next prime is 261225647. The reversal of 261225645 is 546522162.

It is not a de Polignac number, because 261225645 - 2² = 261225641 is a prime.

It is a super-3 number, since 3×261225645³ (a number of 26 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261225641) 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, 201856 + ... + 203145.

It is an arithmetic number, because the mean of its divisors is an integer number (26730132).

Almost surely, 2^261225645 is an apocalyptic number.

It is an amenable number.

261225645 is a deficient number, since it is larger than the sum of its proper divisors (166456467).

261225645 is a wasteful number, since it uses less digits than its factorization.

261225645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 405052.

The product of its digits is 28800, while the sum is 33.

The square root of 261225645 is about 16162.4764500989. The cubic root of 261225645 is about 639.2517663574.

The spelling of 261225645 in words is "two hundred sixty-one million, two hundred twenty-five thousand, six hundred forty-five".