1261525061 has 4 divisors (see below), whose sum is σ = 1274530572. Its totient is φ = 1248519552.

The previous prime is 1261525043. The next prime is 1261525063. The reversal of 1261525061 is 1605251621.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1605251621 = 1061 ⋅1512961.

It can be written as a sum of positive squares in 2 ways, for example, as 180364900 + 1081160161 = 13430^2 + 32881^2 .

It is a cyclic number.

It is not a de Polignac number, because 1261525061 - 2⁶ = 1261524997 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 (1261525063) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6502610 + ... + 6502803.

It is an arithmetic number, because the mean of its divisors is an integer number (318632643).

Almost surely, 2^1261525061 is an apocalyptic number.

It is an amenable number.

1261525061 is a deficient number, since it is larger than the sum of its proper divisors (13005511).

1261525061 is an equidigital number, since it uses as much as digits as its factorization.

1261525061 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13005510.

The product of its (nonzero) digits is 3600, while the sum is 29.

The square root of 1261525061 is about 35517.9540655145. The cubic root of 1261525061 is about 1080.5178874797.

Adding to 1261525061 its reverse (1605251621), we get a palindrome (2866776682).

The spelling of 1261525061 in words is "one billion, two hundred sixty-one million, five hundred twenty-five thousand, sixty-one".