261573049 has 2 divisors, whose sum is σ = 261573050. Its totient is φ = 261573048.

The previous prime is 261573041. The next prime is 261573061. The reversal of 261573049 is 940375162.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 200420649 + 61152400 = 14157^2 + 7820^2 .

It is a cyclic number.

It is not a de Polignac number, because 261573049 - 2³ = 261573041 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 261572999 and 261573017.

It is not a weakly prime, because it can be changed into another prime (261573041) by changing a digit.

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 as a sum of consecutive naturals, namely, 130786524 + 130786525.

It is an arithmetic number, because the mean of its divisors is an integer number (130786525).

Almost surely, 2^261573049 is an apocalyptic number.

It is an amenable number.

261573049 is a deficient number, since it is larger than the sum of its proper divisors (1).

261573049 is an equidigital number, since it uses as much as digits as its factorization.

261573049 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 45360, while the sum is 37.

The square root of 261573049 is about 16173.2201184551. The cubic root of 261573049 is about 639.5350211477.

The spelling of 261573049 in words is "two hundred sixty-one million, five hundred seventy-three thousand, forty-nine".