21103534 has 4 divisors (see below), whose sum is σ = 31655304. Its totient is φ = 10551766.

The previous prime is 21103531. The next prime is 21103549. The reversal of 21103534 is 43530112.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21103531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5275882 + ... + 5275885.

It is an arithmetic number, because the mean of its divisors is an integer number (7913826).

Almost surely, 2^21103534 is an apocalyptic number.

21103534 is a deficient number, since it is larger than the sum of its proper divisors (10551770).

21103534 is a wasteful number, since it uses less digits than its factorization.

21103534 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10551769.

The product of its (nonzero) digits is 360, while the sum is 19.

The square root of 21103534 is about 4593.8582912406. The cubic root of 21103534 is about 276.3450752783.

Adding to 21103534 its reverse (43530112), we get a palindrome (64633646).

The spelling of 21103534 in words is "twenty-one million, one hundred three thousand, five hundred thirty-four".