145661440 has 80 divisors (see below), whose sum is σ = 369900432. Its totient is φ = 54820864.

The previous prime is 145661419. The next prime is 145661441. The reversal of 145661440 is 44166541.

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (145661441) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 41847 + ... + 45193.

Almost surely, 2^145661440 is an apocalyptic number.

145661440 is a gapful number since it is divisible by the number (10) 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 145661440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (184950216).

145661440 is an abundant number, since it is smaller than the sum of its proper divisors (224238992).

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

145661440 is an equidigital number, since it uses as much as digits as its factorization.

145661440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3387 (or 3371 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 31.

The square root of 145661440 is about 12069.0281298868. The cubic root of 145661440 is about 526.1564108577.

The spelling of 145661440 in words is "one hundred forty-five million, six hundred sixty-one thousand, four hundred forty".