61855911 has 48 divisors (see below), whose sum is σ = 103076064. Its totient is φ = 35407872.

The previous prime is 61855909. The next prime is 61855919. The reversal of 61855911 is 11955816.

61855911 is a `hidden beast` number, since 61 + 8 + 5 + 591 + 1 = 666.

It is not a de Polignac number, because 61855911 - 2¹ = 61855909 is a prime.

It is a super-4 number, since 4×61855911⁴ (a number of 32 digits) contains 4444 as substring.

Its product of digits (10800) is a multiple of the sum of its prime factors (400).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61855919) 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 47 ways as a sum of consecutive naturals, for example, 272380 + ... + 272606.

It is an arithmetic number, because the mean of its divisors is an integer number (2147418).

Almost surely, 2^61855911 is an apocalyptic number.

61855911 is a deficient number, since it is larger than the sum of its proper divisors (41220153).

61855911 is a wasteful number, since it uses less digits than its factorization.

61855911 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 400 (or 397 counting only the distinct ones).

The product of its digits is 10800, while the sum is 36.

The square root of 61855911 is about 7864.8528911862. The cubic root of 61855911 is about 395.4823163433.

The spelling of 61855911 in words is "sixty-one million, eight hundred fifty-five thousand, nine hundred eleven".