20378947 has 4 divisors (see below), whose sum is σ = 20852920. Its totient is φ = 19904976.

The previous prime is 20378933. The next prime is 20378951. The reversal of 20378947 is 74987302.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20378947 - 2²³ = 11990339 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20378957) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 236922 + ... + 237007.

It is an arithmetic number, because the mean of its divisors is an integer number (5213230).

Almost surely, 2^20378947 is an apocalyptic number.

20378947 is a deficient number, since it is larger than the sum of its proper divisors (473973).

20378947 is an equidigital number, since it uses as much as digits as its factorization.

20378947 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 473972.

The product of its (nonzero) digits is 84672, while the sum is 40.

The square root of 20378947 is about 4514.3047083687. The cubic root of 20378947 is about 273.1454139954.

The spelling of 20378947 in words is "twenty million, three hundred seventy-eight thousand, nine hundred forty-seven".