261420478 has 16 divisors (see below), whose sum is σ = 437728896. Its totient is φ = 116063640.

The previous prime is 261420463. The next prime is 261420479. The reversal of 261420478 is 874024162.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261420479) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 137226 + ... + 139117.

It is an arithmetic number, because the mean of its divisors is an integer number (27358056).

Almost surely, 2^261420478 is an apocalyptic number.

261420478 is a deficient number, since it is larger than the sum of its proper divisors (176308418).

261420478 is a wasteful number, since it uses less digits than its factorization.

261420478 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 276399.

The product of its (nonzero) digits is 21504, while the sum is 34.

The square root of 261420478 is about 16168.5026517609. The cubic root of 261420478 is about 639.4106537541.

The spelling of 261420478 in words is "two hundred sixty-one million, four hundred twenty thousand, four hundred seventy-eight".