21746225 has 6 divisors (see below), whose sum is σ = 26965350. Its totient is φ = 17396960.

The previous prime is 21746183. The next prime is 21746233. The reversal of 21746225 is 52264712.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 7054336 + 14691889 = 2656^2 + 3833^2 .

It is not a de Polignac number, because 21746225 - 2¹⁰ = 21745201 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 434900 + ... + 434949.

It is an arithmetic number, because the mean of its divisors is an integer number (4494225).

Almost surely, 2^21746225 is an apocalyptic number.

21746225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21746225 is a deficient number, since it is larger than the sum of its proper divisors (5219125).

21746225 is an equidigital number, since it uses as much as digits as its factorization.

21746225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 869859 (or 869854 counting only the distinct ones).

The product of its digits is 6720, while the sum is 29.

The square root of 21746225 is about 4663.2847864997. The cubic root of 21746225 is about 279.1223582559.

The spelling of 21746225 in words is "twenty-one million, seven hundred forty-six thousand, two hundred twenty-five".