20938947 has 8 divisors (see below), whose sum is σ = 29132544. Its totient is φ = 13352328.

The previous prime is 20938927. The next prime is 20938949. The reversal of 20938947 is 74983902.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20938947 - 2¹⁹ = 20414659 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20938899 and 20938908.

It is not an unprimeable number, because it can be changed into a prime (20938949) 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, 151663 + ... + 151800.

It is an arithmetic number, because the mean of its divisors is an integer number (3641568).

Almost surely, 2^20938947 is an apocalyptic number.

20938947 is a deficient number, since it is larger than the sum of its proper divisors (8193597).

20938947 is a wasteful number, since it uses less digits than its factorization.

20938947 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 303489.

The product of its (nonzero) digits is 108864, while the sum is 42.

The square root of 20938947 is about 4575.9094178098. The cubic root of 20938947 is about 275.6247920875.

The spelling of 20938947 in words is "twenty million, nine hundred thirty-eight thousand, nine hundred forty-seven".