61320561 has 8 divisors (see below), whose sum is σ = 81906720. Its totient is φ = 40807392.

The previous prime is 61320551. The next prime is 61320601. The reversal of 61320561 is 16502316.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 61320561 - 2¹³ = 61312369 is a prime.

It is a super-2 number, since 2×61320561² = 7520422402709442, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (61320541) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16255 + ... + 19668.

It is an arithmetic number, because the mean of its divisors is an integer number (10238340).

Almost surely, 2^61320561 is an apocalyptic number.

It is an amenable number.

61320561 is a deficient number, since it is larger than the sum of its proper divisors (20586159).

61320561 is a wasteful number, since it uses less digits than its factorization.

61320561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36495.

The product of its (nonzero) digits is 1080, while the sum is 24.

The square root of 61320561 is about 7830.7446006111. The cubic root of 61320561 is about 394.3380699260.

Adding to 61320561 its reverse (16502316), we get a palindrome (77822877).

The spelling of 61320561 in words is "sixty-one million, three hundred twenty thousand, five hundred sixty-one".