20918147 has 8 divisors (see below), whose sum is σ = 21226800. Its totient is φ = 20611584.

The previous prime is 20918113. The next prime is 20918189. The reversal of 20918147 is 74181902.

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

It is a cyclic number.

It is not a de Polignac number, because 20918147 - 2⁶ = 20918083 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20918197) 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, 36479 + ... + 37047.

It is an arithmetic number, because the mean of its divisors is an integer number (2653350).

Almost surely, 2^20918147 is an apocalyptic number.

20918147 is a deficient number, since it is larger than the sum of its proper divisors (308653).

20918147 is an equidigital number, since it uses as much as digits as its factorization.

20918147 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1045.

The product of its (nonzero) digits is 4032, while the sum is 32.

The square root of 20918147 is about 4573.6360808442. The cubic root of 20918147 is about 275.5334965854.

The spelling of 20918147 in words is "twenty million, nine hundred eighteen thousand, one hundred forty-seven".