61811455 has 4 divisors (see below), whose sum is σ = 74173752. Its totient is φ = 49449160.

The previous prime is 61811447. The next prime is 61811459. The reversal of 61811455 is 55411816.

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

It is not a de Polignac number, because 61811455 - 2³ = 61811447 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61811459) 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 3 ways as a sum of consecutive naturals, for example, 6181141 + ... + 6181150.

It is an arithmetic number, because the mean of its divisors is an integer number (18543438).

Almost surely, 2^61811455 is an apocalyptic number.

61811455 is a deficient number, since it is larger than the sum of its proper divisors (12362297).

61811455 is a wasteful number, since it uses less digits than its factorization.

61811455 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12362296.

The product of its digits is 4800, while the sum is 31.

The square root of 61811455 is about 7862.0261383437. The cubic root of 61811455 is about 395.3875489221.

The spelling of 61811455 in words is "sixty-one million, eight hundred eleven thousand, four hundred fifty-five".