261605426 has 4 divisors (see below), whose sum is σ = 392408142. Its totient is φ = 130802712.

The previous prime is 261605417. The next prime is 261605437. The reversal of 261605426 is 624506162.

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

It can be written as a sum of positive squares in only one way, i.e., 186349801 + 75255625 = 13651^2 + 8675^2 .

It is a junction number, because it is equal to n+sod(n) for n = 261605392 and 261605401.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 65401355 + ... + 65401358.

Almost surely, 2^261605426 is an apocalyptic number.

261605426 is a deficient number, since it is larger than the sum of its proper divisors (130802716).

261605426 is a wasteful number, since it uses less digits than its factorization.

261605426 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 130802715.

The product of its (nonzero) digits is 17280, while the sum is 32.

The square root of 261605426 is about 16174.2210322476. The cubic root of 261605426 is about 639.5614068568.

The spelling of 261605426 in words is "two hundred sixty-one million, six hundred five thousand, four hundred twenty-six".