253861 has 8 divisors (see below), whose sum is σ = 273240. Its totient is φ = 235008.

The previous prime is 253853. The next prime is 253867. The reversal of 253861 is 168352.

253861 = 44² + 45² + ... + 94².

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 101761 + 152100 = 319^2 + 390^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 253861 - 2³ = 253853 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (253867) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1785 + ... + 1921.

It is an arithmetic number, because the mean of its divisors is an integer number (34155).

2²⁵³⁸⁶¹ is an apocalyptic number.

It is an amenable number.

253861 is a deficient number, since it is larger than the sum of its proper divisors (19379).

253861 is a wasteful number, since it uses less digits than its factorization.

253861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 263.

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

The square root of 253861 is about 503.8462066941. The cubic root of 253861 is about 63.3187008363.

The spelling of 253861 in words is "two hundred fifty-three thousand, eight hundred sixty-one".