21652881 has 8 divisors (see below), whose sum is σ = 29650944. Its totient is φ = 14045040.

The previous prime is 21652871. The next prime is 21652901. The reversal of 21652881 is 18825612.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21652881 - 2²² = 17458577 is a prime.

It is a super-2 number, since 2×21652881² = 937694511200322, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21652801) 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 7 ways as a sum of consecutive naturals, for example, 97425 + ... + 97646.

It is an arithmetic number, because the mean of its divisors is an integer number (3706368).

Almost surely, 2^21652881 is an apocalyptic number.

It is an amenable number.

21652881 is a deficient number, since it is larger than the sum of its proper divisors (7998063).

21652881 is a wasteful number, since it uses less digits than its factorization.

21652881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 195111.

The product of its digits is 7680, while the sum is 33.

The square root of 21652881 is about 4653.2656274922. The cubic root of 21652881 is about 278.7224150413.

The spelling of 21652881 in words is "twenty-one million, six hundred fifty-two thousand, eight hundred eighty-one".