61855791 has 8 divisors (see below), whose sum is σ = 83021184. Its totient is φ = 40963800.

The previous prime is 61855789. The next prime is 61855793. The reversal of 61855791 is 19755816.

It is an interprime number because it is at equal distance from previous prime (61855789) and next prime (61855793).

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

It is not a de Polignac number, because 61855791 - 2¹ = 61855789 is a prime.

It is a super-2 number, since 2×61855791² = 7652277760471362, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61855793) 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 7 ways as a sum of consecutive naturals, for example, 67821 + ... + 68726.

It is an arithmetic number, because the mean of its divisors is an integer number (10377648).

Almost surely, 2^61855791 is an apocalyptic number.

61855791 is a deficient number, since it is larger than the sum of its proper divisors (21165393).

61855791 is a wasteful number, since it uses less digits than its factorization.

61855791 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 136701.

The product of its digits is 75600, while the sum is 42.

The square root of 61855791 is about 7864.8452623049. The cubic root of 61855791 is about 395.4820605989.

The spelling of 61855791 in words is "sixty-one million, eight hundred fifty-five thousand, seven hundred ninety-one".