20350640 has 20 divisors (see below), whose sum is σ = 47315424. Its totient is φ = 8140224.

The previous prime is 20350639. The next prime is 20350643. The reversal of 20350640 is 4605302.

It is a tau number, because it is divible by the number of its divisors (20).

It is a Harshad number since it is a multiple of its sum of digits (20).

It is not an unprimeable number, because it can be changed into a prime (20350643) 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 3 ways as a sum of consecutive naturals, for example, 127112 + ... + 127271.

Almost surely, 2^20350640 is an apocalyptic number.

20350640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20350640 is an abundant number, since it is smaller than the sum of its proper divisors (26964784).

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

20350640 is a wasteful number, since it uses less digits than its factorization.

20350640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 254396 (or 254390 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 20.

The square root of 20350640 is about 4511.1683630740. The cubic root of 20350640 is about 273.0188861958.

Adding to 20350640 its reverse (4605302), we get a palindrome (24955942).

The spelling of 20350640 in words is "twenty million, three hundred fifty thousand, six hundred forty".