61811155 has 16 divisors (see below), whose sum is σ = 84962304. Its totient is φ = 42288480.

The previous prime is 61811153. The next prime is 61811159. The reversal of 61811155 is 55111816.

It is not a de Polignac number, because 61811155 - 2¹ = 61811153 is a prime.

It is not an unprimeable number, because it can be changed into a prime (61811153) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15850 + ... + 19360.

It is an arithmetic number, because the mean of its divisors is an integer number (5310144).

Almost surely, 2^61811155 is an apocalyptic number.

61811155 is a deficient number, since it is larger than the sum of its proper divisors (23151149).

61811155 is a wasteful number, since it uses less digits than its factorization.

61811155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4026.

The product of its digits is 1200, while the sum is 28.

The square root of 61811155 is about 7862.0070592693. The cubic root of 61811155 is about 395.3869092539.

The spelling of 61811155 in words is "sixty-one million, eight hundred eleven thousand, one hundred fifty-five".