21007325 has 12 divisors (see below), whose sum is σ = 27581940. Its totient is φ = 15816960.

The previous prime is 21007321. The next prime is 21007423. The reversal of 21007325 is 52370012.

It can be written as a sum of positive squares in 6 ways, for example, as 85849 + 20921476 = 293^2 + 4574^2 .

It is not a de Polignac number, because 21007325 - 2² = 21007321 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21007297 and 21007306.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21007321) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 24290 + ... + 25139.

It is an arithmetic number, because the mean of its divisors is an integer number (2298495).

Almost surely, 2^21007325 is an apocalyptic number.

21007325 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21007325 is a deficient number, since it is larger than the sum of its proper divisors (6574615).

21007325 is a wasteful number, since it uses less digits than its factorization.

21007325 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49456 (or 49451 counting only the distinct ones).

The product of its (nonzero) digits is 420, while the sum is 20.

The square root of 21007325 is about 4583.3748482968. The cubic root of 21007325 is about 275.9244918767.

Adding to 21007325 its reverse (52370012), we get a palindrome (73377337).

The spelling of 21007325 in words is "twenty-one million, seven thousand, three hundred twenty-five".