90699840 has 336 divisors, whose sum is σ = 389900160. Its totient is φ = 18800640.

The previous prime is 90699809. The next prime is 90699841. The reversal of 90699840 is 4899609.

It is a tau number, because it is divible by the number of its divisors (336).

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (90699841) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 221556 + ... + 221964.

Almost surely, 2^90699840 is an apocalyptic number.

90699840 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 90699840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (194950080).

90699840 is an abundant number, since it is smaller than the sum of its proper divisors (299200320).

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

90699840 is a wasteful number, since it uses less digits than its factorization.

90699840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 450 (or 437 counting only the distinct ones).

The product of its (nonzero) digits is 139968, while the sum is 45.

The square root of 90699840 is about 9523.6463605071. The cubic root of 90699840 is about 449.2990568901.

The spelling of 90699840 in words is "ninety million, six hundred ninety-nine thousand, eight hundred forty".