61561313 has 4 divisors (see below), whose sum is σ = 67157808. Its totient is φ = 55964820.

The previous prime is 61561307. The next prime is 61561321. The reversal of 61561313 is 31316516.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 61561313 - 2¹⁸ = 61299169 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61561343) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2798231 + ... + 2798252.

It is an arithmetic number, because the mean of its divisors is an integer number (16789452).

Almost surely, 2^61561313 is an apocalyptic number.

It is an amenable number.

61561313 is a deficient number, since it is larger than the sum of its proper divisors (5596495).

61561313 is a wasteful number, since it uses less digits than its factorization.

61561313 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5596494.

The product of its digits is 1620, while the sum is 26.

The square root of 61561313 is about 7846.1017709433. The cubic root of 61561313 is about 394.8534691228.

Adding to 61561313 its reverse (31316516), we get a palindrome (92877829).

The spelling of 61561313 in words is "sixty-one million, five hundred sixty-one thousand, three hundred thirteen".