61521361 has 12 divisors (see below), whose sum is σ = 69277572. Its totient is φ = 54560000.

The previous prime is 61521359. The next prime is 61521379. The reversal of 61521361 is 16312516.

It can be written as a sum of positive squares in 2 ways, for example, as 11182336 + 50339025 = 3344^2 + 7095^2 .

It is not a de Polignac number, because 61521361 - 2¹ = 61521359 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61521301) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1240 + ... + 11161.

It is an arithmetic number, because the mean of its divisors is an integer number (5773131).

Almost surely, 2^61521361 is an apocalyptic number.

61521361 is the 4961-st heptagonal number.

It is an amenable number.

61521361 is a deficient number, since it is larger than the sum of its proper divisors (7756211).

61521361 is a wasteful number, since it uses less digits than its factorization.

61521361 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12464 (or 12453 counting only the distinct ones).

The product of its digits is 1080, while the sum is 25.

The square root of 61521361 is about 7843.5553800557. Note that the first 3 decimals coincide. The cubic root of 61521361 is about 394.7680334336.

Adding to 61521361 its reverse (16312516), we get a palindrome (77833877).

The spelling of 61521361 in words is "sixty-one million, five hundred twenty-one thousand, three hundred sixty-one".