21048881 has 16 divisors (see below), whose sum is σ = 24816000. Its totient is φ = 17844624.

The previous prime is 21048857. The next prime is 21048889. The reversal of 21048881 is 18884012.

It is a de Polignac number, because none of the positive numbers 2^k-21048881 is a prime.

It is a super-2 number, since 2×21048881² = 886110782704322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21048889) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 37106 + ... + 37668.

It is an arithmetic number, because the mean of its divisors is an integer number (1551000).

Almost surely, 2^21048881 is an apocalyptic number.

It is an amenable number.

21048881 is a deficient number, since it is larger than the sum of its proper divisors (3767119).

21048881 is an equidigital number, since it uses as much as digits as its factorization.

21048881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 693 (or 679 counting only the distinct ones).

The product of its (nonzero) digits is 4096, while the sum is 32.

The square root of 21048881 is about 4587.9059493412. The cubic root of 21048881 is about 276.1063136257.

The spelling of 21048881 in words is "twenty-one million, forty-eight thousand, eight hundred eighty-one".