61878161 has 4 divisors (see below), whose sum is σ = 63317232. Its totient is φ = 60439092.

The previous prime is 61878151. The next prime is 61878163. The reversal of 61878161 is 16187816.

61878161 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 61878161 - 2¹⁸ = 61616017 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (61878163) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 719471 + ... + 719556.

It is an arithmetic number, because the mean of its divisors is an integer number (15829308).

Almost surely, 2^61878161 is an apocalyptic number.

It is an amenable number.

61878161 is a deficient number, since it is larger than the sum of its proper divisors (1439071).

61878161 is a wasteful number, since it uses less digits than its factorization.

61878161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1439070.

The product of its digits is 16128, while the sum is 38.

The square root of 61878161 is about 7866.2672850597. The cubic root of 61878161 is about 395.5297299023.

The spelling of 61878161 in words is "sixty-one million, eight hundred seventy-eight thousand, one hundred sixty-one".