20916838 has 4 divisors (see below), whose sum is σ = 31375260. Its totient is φ = 10458418.

The previous prime is 20916829. The next prime is 20916871. The reversal of 20916838 is 83861902.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 83861902 = 2 ⋅41930951.

It is a super-3 number, since 3×20916838³ (a number of 23 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a junction number, because it is equal to n+sod(n) for n = 20916797 and 20916806.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5229208 + ... + 5229211.

It is an arithmetic number, because the mean of its divisors is an integer number (7843815).

Almost surely, 2^20916838 is an apocalyptic number.

20916838 is a deficient number, since it is larger than the sum of its proper divisors (10458422).

20916838 is a wasteful number, since it uses less digits than its factorization.

20916838 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10458421.

The product of its (nonzero) digits is 20736, while the sum is 37.

The square root of 20916838 is about 4573.4929758337. The cubic root of 20916838 is about 275.5277490898.

The spelling of 20916838 in words is "twenty million, nine hundred sixteen thousand, eight hundred thirty-eight".