90636840 has 256 divisors, whose sum is σ = 364032000. Its totient is φ = 19595520.

The previous prime is 90636817. The next prime is 90636841. The reversal of 90636840 is 4863609.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 90636795 and 90636804.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (90636841) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 143325 + ... + 143955.

It is an arithmetic number, because the mean of its divisors is an integer number (1422000).

Almost surely, 2^90636840 is an apocalyptic number.

90636840 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 90636840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (182016000).

90636840 is an abundant number, since it is smaller than the sum of its proper divisors (273395160).

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

90636840 is a wasteful number, since it uses less digits than its factorization.

90636840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 677 (or 667 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 36.

The square root of 90636840 is about 9520.3382292858. The cubic root of 90636840 is about 449.1950052664.

The spelling of 90636840 in words is "ninety million, six hundred thirty-six thousand, eight hundred forty".