90866820 has 144 divisors (see below), whose sum is σ = 289808064. Its totient is φ = 21081600.

The previous prime is 90866801. The next prime is 90866843. The reversal of 90866820 is 2866809.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1489590 + ... + 1489650.

It is an arithmetic number, because the mean of its divisors is an integer number (2012556).

Almost surely, 2^90866820 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 90866820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (144904032).

90866820 is an abundant number, since it is smaller than the sum of its proper divisors (198941244).

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

90866820 is a wasteful number, since it uses less digits than its factorization.

90866820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 182 (or 119 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 39.

The square root of 90866820 is about 9532.4089295414. The cubic root of 90866820 is about 449.5746103472.

Subtracting from 90866820 its reverse (2866809), we obtain a triangular number (88000011 = T₁₃₂₆₆).

The spelling of 90866820 in words is "ninety million, eight hundred sixty-six thousand, eight hundred twenty".