261654861 has 32 divisors (see below), whose sum is σ = 388402560. Its totient is φ = 155637504.

The previous prime is 261654859. The next prime is 261654901. The reversal of 261654861 is 168456162.

It is a happy number.

261654861 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 261654861 - 2¹ = 261654859 is a prime.

It is a Smith number, since the sum of its digits (39) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261654821) 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, 257791 + ... + 258803.

It is an arithmetic number, because the mean of its divisors is an integer number (12137580).

Almost surely, 2^261654861 is an apocalyptic number.

It is an amenable number.

261654861 is a deficient number, since it is larger than the sum of its proper divisors (126747699).

261654861 is a wasteful number, since it uses less digits than its factorization.

261654861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1245.

The product of its digits is 69120, while the sum is 39.

The square root of 261654861 is about 16175.7491634854. The cubic root of 261654861 is about 639.6016898220.

The spelling of 261654861 in words is "two hundred sixty-one million, six hundred fifty-four thousand, eight hundred sixty-one".