261231144 has 32 divisors (see below), whose sum is σ = 659076000. Its totient is φ = 86277312.

The previous prime is 261231143. The next prime is 261231151. The reversal of 261231144 is 441132162.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (261231143) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 47314 + ... + 52545.

It is an arithmetic number, because the mean of its divisors is an integer number (20596125).

Almost surely, 2^261231144 is an apocalyptic number.

261231144 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

261231144 is an abundant number, since it is smaller than the sum of its proper divisors (397844856).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

261231144 is a wasteful number, since it uses less digits than its factorization.

261231144 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 99977 (or 99973 counting only the distinct ones).

The product of its digits is 1152, while the sum is 24.

The square root of 261231144 is about 16162.6465654607. The cubic root of 261231144 is about 639.2562519058.

The spelling of 261231144 in words is "two hundred sixty-one million, two hundred thirty-one thousand, one hundred forty-four".