261869378 has 16 divisors (see below), whose sum is σ = 402845184. Its totient is φ = 127595040.

The previous prime is 261869359. The next prime is 261869389. The reversal of 261869378 is 873968162.

It is a super-2 number, since 2×261869378² = 137151142268213768, which contains 22 as substring.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 117551 + ... + 119757.

It is an arithmetic number, because the mean of its divisors is an integer number (25177824).

Almost surely, 2^261869378 is an apocalyptic number.

261869378 is a deficient number, since it is larger than the sum of its proper divisors (140975806).

261869378 is a wasteful number, since it uses less digits than its factorization.

261869378 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3697.

The product of its digits is 870912, while the sum is 50.

The square root of 261869378 is about 16182.3786261476. The cubic root of 261869378 is about 639.7764339568.

The spelling of 261869378 in words is "two hundred sixty-one million, eight hundred sixty-nine thousand, three hundred seventy-eight".