20353440 has 48 divisors (see below), whose sum is σ = 64114848. Its totient is φ = 5427456.

The previous prime is 20353429. The next prime is 20353483. The reversal of 20353440 is 4435302.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (48).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20722 + ... + 21681.

It is an arithmetic number, because the mean of its divisors is an integer number (1335726).

Almost surely, 2^20353440 is an apocalyptic number.

20353440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20353440 is an abundant number, since it is smaller than the sum of its proper divisors (43761408).

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

20353440 is a wasteful number, since it uses less digits than its factorization.

20353440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42421 (or 42413 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 21.

The square root of 20353440 is about 4511.4786932889. The cubic root of 20353440 is about 273.0314069785.

Adding to 20353440 its reverse (4435302), we get a palindrome (24788742).

The spelling of 20353440 in words is "twenty million, three hundred fifty-three thousand, four hundred forty".