145221640 has 32 divisors (see below), whose sum is σ = 329112000. Its totient is φ = 57668544.

The previous prime is 145221623. The next prime is 145221649. The reversal of 145221640 is 46122541.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (145221649) 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, 7500 + ... + 18619.

It is an arithmetic number, because the mean of its divisors is an integer number (10284750).

Almost surely, 2^145221640 is an apocalyptic number.

145221640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

145221640 is an abundant number, since it is smaller than the sum of its proper divisors (183890360).

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

145221640 is a wasteful number, since it uses less digits than its factorization.

145221640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26269 (or 26265 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 25.

The square root of 145221640 is about 12050.7941647013. The cubic root of 145221640 is about 525.6263303378.

Subtracting from 145221640 its reverse (46122541), we obtain a palindrome (99099099).

The spelling of 145221640 in words is "one hundred forty-five million, two hundred twenty-one thousand, six hundred forty".