21602425 has 18 divisors (see below), whose sum is σ = 29011722. Its totient is φ = 15949440.

The previous prime is 21602423. The next prime is 21602431. The reversal of 21602425 is 52420612.

It can be written as a sum of positive squares in 9 ways, for example, as 19686969 + 1915456 = 4437^2 + 1384^2 .

It is not a de Polignac number, because 21602425 - 2¹ = 21602423 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21602396 and 21602405.

It is not an unprimeable number, because it can be changed into a prime (21602423) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 1669 + ... + 6781.

Almost surely, 2^21602425 is an apocalyptic number.

21602425 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21602425 is a deficient number, since it is larger than the sum of its proper divisors (7409297).

21602425 is a wasteful number, since it uses less digits than its factorization.

21602425 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5149 (or 5131 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 22.

The square root of 21602425 is about 4647.8408965884. The cubic root of 21602425 is about 278.5057517128.

The spelling of 21602425 in words is "twenty-one million, six hundred two thousand, four hundred twenty-five".