21294025 has 6 divisors (see below), whose sum is σ = 26404622. Its totient is φ = 17035200.

The previous prime is 21294001. The next prime is 21294029. The reversal of 21294025 is 52049212.

It can be written as a sum of positive squares in 3 ways, for example, as 1411344 + 19882681 = 1188^2 + 4459^2 .

It is a de Polignac number, because none of the positive numbers 2^k-21294025 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (25), and also a Moran number because the ratio is a prime number: 851761 = 21294025 / (2 + 1 + 2 + 9 + 4 + 0 + 2 + 5).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21294029) 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 5 ways as a sum of consecutive naturals, for example, 425856 + ... + 425905.

Almost surely, 2^21294025 is an apocalyptic number.

21294025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21294025 is a deficient number, since it is larger than the sum of its proper divisors (5110597).

21294025 is an equidigital number, since it uses as much as digits as its factorization.

21294025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 851771 (or 851766 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 25.

The square root of 21294025 is about 4614.5449396446. The cubic root of 21294025 is about 277.1740620340.

The spelling of 21294025 in words is "twenty-one million, two hundred ninety-four thousand, twenty-five".