21425735 has 4 divisors (see below), whose sum is σ = 25710888. Its totient is φ = 17140584.

The previous prime is 21425707. The next prime is 21425759. The reversal of 21425735 is 53752412.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21425735 - 2⁶ = 21425671 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21425698 and 21425707.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2142569 + ... + 2142578.

It is an arithmetic number, because the mean of its divisors is an integer number (6427722).

Almost surely, 2^21425735 is an apocalyptic number.

21425735 is a deficient number, since it is larger than the sum of its proper divisors (4285153).

21425735 is an equidigital number, since it uses as much as digits as its factorization.

21425735 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4285152.

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

The square root of 21425735 is about 4628.7941194225. The cubic root of 21425735 is about 277.7443563642.

The spelling of 21425735 in words is "twenty-one million, four hundred twenty-five thousand, seven hundred thirty-five".