20647938 has 16 divisors (see below), whose sum is σ = 41389920. Its totient is φ = 6866976.

The previous prime is 20647933. The next prime is 20647943. The reversal of 20647938 is 83974602.

It is an interprime number because it is at equal distance from previous prime (20647933) and next prime (20647943).

It is a junction number, because it is equal to n+sod(n) for n = 20647896 and 20647905.

It is not an unprimeable number, because it can be changed into a prime (20647933) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 883 + ... + 6486.

It is an arithmetic number, because the mean of its divisors is an integer number (2586870).

Almost surely, 2^20647938 is an apocalyptic number.

20647938 is an abundant number, since it is smaller than the sum of its proper divisors (20741982).

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

20647938 is a wasteful number, since it uses less digits than its factorization.

20647938 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7841.

The product of its (nonzero) digits is 72576, while the sum is 39.

The square root of 20647938 is about 4544.0002200704. Note that the first 3 decimals coincide. The cubic root of 20647938 is about 274.3419550007.

The spelling of 20647938 in words is "twenty million, six hundred forty-seven thousand, nine hundred thirty-eight".