21535854 has 16 divisors (see below), whose sum is σ = 45338880. Its totient is φ = 6800760.

The previous prime is 21535849. The next prime is 21535859. The reversal of 21535854 is 45853512.

It is an interprime number because it is at equal distance from previous prime (21535849) and next prime (21535859).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21535859) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 94342 + ... + 94569.

It is an arithmetic number, because the mean of its divisors is an integer number (2833680).

Almost surely, 2^21535854 is an apocalyptic number.

21535854 is an abundant number, since it is smaller than the sum of its proper divisors (23803026).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21535854 is a wasteful number, since it uses less digits than its factorization.

21535854 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 188935.

The product of its digits is 24000, while the sum is 33.

The square root of 21535854 is about 4640.6738734800. The cubic root of 21535854 is about 278.2193720733.

The spelling of 21535854 in words is "twenty-one million, five hundred thirty-five thousand, eight hundred fifty-four".