61521261 has 32 divisors (see below), whose sum is σ = 87521280. Its totient is φ = 38392704.

The previous prime is 61521241. The next prime is 61521277. The reversal of 61521261 is 16212516.

It is not a de Polignac number, because 61521261 - 2⁹ = 61520749 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61521241) 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 in 31 ways as a sum of consecutive naturals, for example, 442530 + ... + 442668.

It is an arithmetic number, because the mean of its divisors is an integer number (2735040).

Almost surely, 2^61521261 is an apocalyptic number.

It is an amenable number.

61521261 is a deficient number, since it is larger than the sum of its proper divisors (26000019).

61521261 is a wasteful number, since it uses less digits than its factorization.

61521261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 305.

The product of its digits is 720, while the sum is 24.

The square root of 61521261 is about 7843.5490053929. The cubic root of 61521261 is about 394.7678195413.

Adding to 61521261 its reverse (16212516), we get a palindrome (77733777).

The spelling of 61521261 in words is "sixty-one million, five hundred twenty-one thousand, two hundred sixty-one".