21735425 has 12 divisors (see below), whose sum is σ = 27580080. Its totient is φ = 16983120.

The previous prime is 21735421. The next prime is 21735431. The reversal of 21735425 is 52453712.

It is a happy number.

It is not a de Polignac number, because 21735425 - 2² = 21735421 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21735421) 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, 9035 + ... + 11184.

It is an arithmetic number, because the mean of its divisors is an integer number (2298340).

Almost surely, 2^21735425 is an apocalyptic number.

21735425 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21735425 is a deficient number, since it is larger than the sum of its proper divisors (5844655).

21735425 is a wasteful number, since it uses less digits than its factorization.

21735425 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20272 (or 20267 counting only the distinct ones).

The product of its digits is 8400, while the sum is 29.

The square root of 21735425 is about 4662.1266606561. The cubic root of 21735425 is about 279.0761430216.

The spelling of 21735425 in words is "twenty-one million, seven hundred thirty-five thousand, four hundred twenty-five".