261604477 has 4 divisors (see below), whose sum is σ = 267985116. Its totient is φ = 255223840.

The previous prime is 261604459. The next prime is 261604481. The reversal of 261604477 is 774406162.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 54848836 + 206755641 = 7406^2 + 14379^2 .

It is a cyclic number.

It is not a de Polignac number, because 261604477 - 2¹⁹ = 261080189 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261607477) 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, 3190258 + ... + 3190339.

It is an arithmetic number, because the mean of its divisors is an integer number (66996279).

Almost surely, 2^261604477 is an apocalyptic number.

It is an amenable number.

261604477 is a deficient number, since it is larger than the sum of its proper divisors (6380639).

261604477 is an equidigital number, since it uses as much as digits as its factorization.

261604477 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6380638.

The product of its (nonzero) digits is 56448, while the sum is 37.

The square root of 261604477 is about 16174.1916954140. The cubic root of 261604477 is about 639.5606334981.

The spelling of 261604477 in words is "two hundred sixty-one million, six hundred four thousand, four hundred seventy-seven".