61866090 has 288 divisors, whose sum is σ = 209139840. Its totient is φ = 12545280.

The previous prime is 61866083. The next prime is 61866107. The reversal of 61866090 is 9066816.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 2689819 + ... + 2689841.

It is an arithmetic number, because the mean of its divisors is an integer number (726180).

Almost surely, 2^61866090 is an apocalyptic number.

It is a pronic number, being equal to 7865×7866.

It is a practical number, because each smaller number is the sum of distinct divisors of 61866090, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (104569920).

61866090 is an abundant number, since it is smaller than the sum of its proper divisors (147273750).

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

61866090 is a wasteful number, since it uses less digits than its factorization.

61866090 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 90 (or 76 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 36.

The square root of 61866090 is about 7865.4999841078. The cubic root of 61866090 is about 395.5040086582.

Adding to 61866090 its sum of digits (36), we get a triangular number (61866126 = T₁₁₁₂₃).

The spelling of 61866090 in words is "sixty-one million, eight hundred sixty-six thousand, ninety".