90618840 has 288 divisors, whose sum is σ = 341948880. Its totient is φ = 20680704.

The previous prime is 90618839. The next prime is 90618841. The reversal of 90618840 is 4881609.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (90618839) and next prime (90618841).

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 = 90618795 and 90618804.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (90618841) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 1352487 + ... + 1352553.

Almost surely, 2^90618840 is an apocalyptic number.

90618840 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 90618840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (170974440).

90618840 is an abundant number, since it is smaller than the sum of its proper divisors (251330040).

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

90618840 is a wasteful number, since it uses less digits than its factorization.

90618840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 131 (or 107 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 36.

The square root of 90618840 is about 9519.3928377812. The cubic root of 90618840 is about 449.1652673754.

The spelling of 90618840 in words is "ninety million, six hundred eighteen thousand, eight hundred forty".