20910947 has 4 divisors (see below), whose sum is σ = 20963496. Its totient is φ = 20858400.

The previous prime is 20910941. The next prime is 20910961. The reversal of 20910947 is 74901902.

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 20910947 - 2¹⁰ = 20909923 is a prime.

It is a super-3 number, since 3×20910947³ (a number of 23 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20910941) 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, 25673 + ... + 26474.

It is an arithmetic number, because the mean of its divisors is an integer number (5240874).

Almost surely, 2^20910947 is an apocalyptic number.

20910947 is a deficient number, since it is larger than the sum of its proper divisors (52549).

20910947 is an equidigital number, since it uses as much as digits as its factorization.

20910947 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52548.

The product of its (nonzero) digits is 4536, while the sum is 32.

The square root of 20910947 is about 4572.8488931956. The cubic root of 20910947 is about 275.5018801962.

The spelling of 20910947 in words is "twenty million, nine hundred ten thousand, nine hundred forty-seven".