999235440 has 360 divisors, whose sum is σ = 4052084400. Its totient is φ = 228178944.

The previous prime is 999235439. The next prime is 999235451. The reversal of 999235440 is 44532999.

It is a happy number.

999235440 is a `hidden beast` number, since 99 + 92 + 35 + 440 = 666.

It is a tau number, because it is divible by the number of its divisors (360).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 952036 + ... + 953084.

It is an arithmetic number, because the mean of its divisors is an integer number (11255790).

Almost surely, 2^999235440 is an apocalyptic number.

999235440 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 999235440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2026042200).

999235440 is an abundant number, since it is smaller than the sum of its proper divisors (3052848960).

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

999235440 is a wasteful number, since it uses less digits than its factorization.

999235440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1091 (or 1066 counting only the distinct ones).

The product of its (nonzero) digits is 349920, while the sum is 45.

The square root of 999235440 is about 31610.6855351161. The cubic root of 999235440 is about 999.7450816888.

The spelling of 999235440 in words is "nine hundred ninety-nine million, two hundred thirty-five thousand, four hundred forty".