20947225 has 12 divisors (see below), whose sum is σ = 27973036. Its totient is φ = 15468480.

The previous prime is 20947211. The next prime is 20947229. The reversal of 20947225 is 52274902.

It can be written as a sum of positive squares in 6 ways, for example, as 9024016 + 11923209 = 3004^2 + 3453^2 .

It is not a de Polignac number, because 20947225 - 2¹³ = 20939033 is a prime.

It is a hoax number, since the sum of its digits (31) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (20947229) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 31902 + ... + 32551.

Almost surely, 2^20947225 is an apocalyptic number.

20947225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

20947225 is a deficient number, since it is larger than the sum of its proper divisors (7025811).

20947225 is a wasteful number, since it uses less digits than its factorization.

20947225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64476 (or 64471 counting only the distinct ones).

The product of its (nonzero) digits is 10080, while the sum is 31.

The square root of 20947225 is about 4576.8138480825. The cubic root of 20947225 is about 275.6611091227.

The spelling of 20947225 in words is "twenty million, nine hundred forty-seven thousand, two hundred twenty-five".