21117448 has 32 divisors (see below), whose sum is σ = 44593920. Its totient is φ = 9288000.

The previous prime is 21117443. The next prime is 21117463. The reversal of 21117448 is 84471112.

It is a super-2 number, since 2×21117448² = 891893220065408, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21117443) 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, 1143 + ... + 6598.

It is an arithmetic number, because the mean of its divisors is an integer number (1393560).

Almost surely, 2^21117448 is an apocalyptic number.

It is an amenable number.

21117448 is an abundant number, since it is smaller than the sum of its proper divisors (23476472).

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

21117448 is a wasteful number, since it uses less digits than its factorization.

21117448 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7789 (or 7785 counting only the distinct ones).

The product of its digits is 1792, while the sum is 28.

The square root of 21117448 is about 4595.3724549812. The cubic root of 21117448 is about 276.4057952923.

It can be divided in two parts, 2111 and 7448, that added together give a palindrome (9559).

The spelling of 21117448 in words is "twenty-one million, one hundred seventeen thousand, four hundred forty-eight".