61218855 has 64 divisors (see below), whose sum is σ = 118656000. Its totient is φ = 29828736.

The previous prime is 61218851. The next prime is 61218877. The reversal of 61218855 is 55881216.

It is not a de Polignac number, because 61218855 - 2² = 61218851 is a prime.

It is a super-2 number, since 2×61218855² = 7495496415022050, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61218851) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 73974 + ... + 74796.

It is an arithmetic number, because the mean of its divisors is an integer number (1854000).

Almost surely, 2^61218855 is an apocalyptic number.

61218855 is a deficient number, since it is larger than the sum of its proper divisors (57437145).

61218855 is a wasteful number, since it uses less digits than its factorization.

61218855 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 885 (or 879 counting only the distinct ones).

The product of its digits is 19200, while the sum is 36.

The square root of 61218855 is about 7824.2478871774. The cubic root of 61218855 is about 394.1199335127.

The spelling of 61218855 in words is "sixty-one million, two hundred eighteen thousand, eight hundred fifty-five".