21113554 has 32 divisors (see below), whose sum is σ = 40061952. Its totient is φ = 8106000.

The previous prime is 21113549. The next prime is 21113581. The reversal of 21113554 is 45531112.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (22).

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, 9969 + ... + 11899.

It is an arithmetic number, because the mean of its divisors is an integer number (1251936).

Almost surely, 2^21113554 is an apocalyptic number.

21113554 is a deficient number, since it is larger than the sum of its proper divisors (18948398).

21113554 is a wasteful number, since it uses less digits than its factorization.

21113554 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2022.

The product of its digits is 600, while the sum is 22.

The square root of 21113554 is about 4594.9487483540. The cubic root of 21113554 is about 276.3888047556.

Adding to 21113554 its reverse (45531112), we get a palindrome (66644666).

It can be divided in two parts, 2111 and 3554, that added together give a palindrome (5665).

The spelling of 21113554 in words is "twenty-one million, one hundred thirteen thousand, five hundred fifty-four".