261831442 has 8 divisors (see below), whose sum is σ = 395383500. Its totient is φ = 130036944.

The previous prime is 261831391. The next prime is 261831443. The reversal of 261831442 is 244138162.

It can be written as a sum of positive squares in 2 ways, for example, as 259177801 + 2653641 = 16099^2 + 1629^2 .

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

It is not an unprimeable number, because it can be changed into a prime (261831443) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 439017 + ... + 439612.

Almost surely, 2^261831442 is an apocalyptic number.

261831442 is a deficient number, since it is larger than the sum of its proper divisors (133552058).

261831442 is a wasteful number, since it uses less digits than its factorization.

261831442 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 878780.

The product of its digits is 9216, while the sum is 31.

The square root of 261831442 is about 16181.2064445146. The cubic root of 261831442 is about 639.7455384889.

The spelling of 261831442 in words is "two hundred sixty-one million, eight hundred thirty-one thousand, four hundred forty-two".