261478729 has 8 divisors (see below), whose sum is σ = 267902208. Its totient is φ = 255131520.

The previous prime is 261478687. The next prime is 261478753. The reversal of 261478729 is 927874162.

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

It is a cyclic number.

It is not a de Polignac number, because 261478729 - 2¹⁷ = 261347657 is a prime.

It is a super-2 number, since 2×261478729² = 136742251438910882, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261475729) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12097 + ... + 25870.

It is an arithmetic number, because the mean of its divisors is an integer number (33487776).

Almost surely, 2^261478729 is an apocalyptic number.

It is an amenable number.

261478729 is a deficient number, since it is larger than the sum of its proper divisors (6423479).

261478729 is an equidigital number, since it uses as much as digits as its factorization.

261478729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38135.

The product of its digits is 338688, while the sum is 46.

The square root of 261478729 is about 16170.3039241691. The cubic root of 261478729 is about 639.4581424387.

The spelling of 261478729 in words is "two hundred sixty-one million, four hundred seventy-eight thousand, seven hundred twenty-nine".