20345040 has 80 divisors (see below), whose sum is σ = 70084800. Its totient is φ = 5424768.

The previous prime is 20345033. The next prime is 20345051. The reversal of 20345040 is 4054302.

It is a happy number.

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

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 2550 + ... + 6869.

It is an arithmetic number, because the mean of its divisors is an integer number (876060).

Almost surely, 2^20345040 is an apocalyptic number.

20345040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20345040 is an abundant number, since it is smaller than the sum of its proper divisors (49739760).

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

20345040 is a wasteful number, since it uses less digits than its factorization.

20345040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9441 (or 9429 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 18.

The square root of 20345040 is about 4510.5476385911. The cubic root of 20345040 is about 272.9938411846.

Adding to 20345040 its reverse (4054302), we get a palindrome (24399342).

The spelling of 20345040 in words is "twenty million, three hundred forty-five thousand, forty".