61561839 has 16 divisors (see below), whose sum is σ = 83836800. Its totient is φ = 40170336.

The previous prime is 61561831. The next prime is 61561873. The reversal of 61561839 is 93816516.

It is not a de Polignac number, because 61561839 - 2³ = 61561831 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 61561797 and 61561806.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61561831) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 49477 + ... + 50705.

It is an arithmetic number, because the mean of its divisors is an integer number (5239800).

Almost surely, 2^61561839 is an apocalyptic number.

61561839 is a deficient number, since it is larger than the sum of its proper divisors (22274961).

61561839 is a wasteful number, since it uses less digits than its factorization.

61561839 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1574.

The product of its digits is 38880, while the sum is 39.

The square root of 61561839 is about 7846.1352907020. The cubic root of 61561839 is about 394.8545937053.

The spelling of 61561839 in words is "sixty-one million, five hundred sixty-one thousand, eight hundred thirty-nine".