61550191 has 4 divisors (see below), whose sum is σ = 61722000. Its totient is φ = 61378384.

The previous prime is 61550189. The next prime is 61550197. The reversal of 61550191 is 19105516.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 61550191 - 2¹ = 61550189 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61550197) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 85366 + ... + 86083.

It is an arithmetic number, because the mean of its divisors is an integer number (15430500).

Almost surely, 2^61550191 is an apocalyptic number.

61550191 is a deficient number, since it is larger than the sum of its proper divisors (171809).

61550191 is a wasteful number, since it uses less digits than its factorization.

61550191 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 171808.

The product of its (nonzero) digits is 1350, while the sum is 28.

The square root of 61550191 is about 7845.3929793223. The cubic root of 61550191 is about 394.8296889024.

The spelling of 61550191 in words is "sixty-one million, five hundred fifty thousand, one hundred ninety-one".