21420935 has 16 divisors (see below), whose sum is σ = 28403136. Its totient is φ = 15426048.

The previous prime is 21420887. The next prime is 21420941. The reversal of 21420935 is 53902412.

It is a cyclic number.

It is not a de Polignac number, because 21420935 - 2¹⁰ = 21419911 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3524 + ... + 7433.

It is an arithmetic number, because the mean of its divisors is an integer number (1775196).

Almost surely, 2^21420935 is an apocalyptic number.

21420935 is a deficient number, since it is larger than the sum of its proper divisors (6982201).

21420935 is a wasteful number, since it uses less digits than its factorization.

21420935 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11002.

The product of its (nonzero) digits is 2160, while the sum is 26.

The square root of 21420935 is about 4628.2755968071. The cubic root of 21420935 is about 277.7236138244.

The spelling of 21420935 in words is "twenty-one million, four hundred twenty thousand, nine hundred thirty-five".