61861866 has 32 divisors (see below), whose sum is σ = 138269376. Its totient is φ = 18288000.

The previous prime is 61861841. The next prime is 61861867. The reversal of 61861866 is 66816816.

It is not an unprimeable number, because it can be changed into a prime (61861867) 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, 8725 + ... + 14136.

It is an arithmetic number, because the mean of its divisors is an integer number (4320918).

Almost surely, 2^61861866 is an apocalyptic number.

61861866 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

61861866 is an abundant number, since it is smaller than the sum of its proper divisors (76407510).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

61861866 is a wasteful number, since it uses less digits than its factorization.

61861866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22918.

The product of its digits is 82944, while the sum is 42.

The square root of 61861866 is about 7865.2314651255. The cubic root of 61861866 is about 395.4950072437.

The spelling of 61861866 in words is "sixty-one million, eight hundred sixty-one thousand, eight hundred sixty-six".