20642838 has 64 divisors (see below), whose sum is σ = 45619200. Its totient is φ = 6209280.

The previous prime is 20642837. The next prime is 20642851. The reversal of 20642838 is 83824602.

It is a super-2 number, since 2×20642838² = 852253521388488, which contains 22 as substring.

20642838 is a modest number, since divided by 2838 gives 2064 as remainder.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 20642799 and 20642808.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20642833) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 231898 + ... + 231986.

It is an arithmetic number, because the mean of its divisors is an integer number (712800).

Almost surely, 2^20642838 is an apocalyptic number.

20642838 is an abundant number, since it is smaller than the sum of its proper divisors (24976362).

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

20642838 is a wasteful number, since it uses less digits than its factorization.

20642838 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 197.

The product of its (nonzero) digits is 18432, while the sum is 33.

The square root of 20642838 is about 4543.4390058633. The cubic root of 20642838 is about 274.3193658334.

The spelling of 20642838 in words is "twenty million, six hundred forty-two thousand, eight hundred thirty-eight".