90561240 has 384 divisors, whose sum is σ = 383685120. Its totient is φ = 18817920.

The previous prime is 90561223. The next prime is 90561241. The reversal of 90561240 is 4216509.

90561240 is a `hidden beast` number, since 9 + 0 + 5 + 612 + 40 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (90561241) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 8232835 + ... + 8232845.

It is an arithmetic number, because the mean of its divisors is an integer number (999180).

Almost surely, 2^90561240 is an apocalyptic number.

90561240 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 90561240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (191842560).

90561240 is an abundant number, since it is smaller than the sum of its proper divisors (293123880).

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

90561240 is a wasteful number, since it uses less digits than its factorization.

90561240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66 (or 28 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 27.

The square root of 90561240 is about 9516.3669538327. The cubic root of 90561240 is about 449.0700796529.

Adding to 90561240 its reverse (4216509), we get a palindrome (94777749).

It can be divided in two parts, 9056 and 1240, that added together give a triangular number (10296 = T₁₄₃).

The spelling of 90561240 in words is "ninety million, five hundred sixty-one thousand, two hundred forty".