21403016 has 32 divisors (see below), whose sum is σ = 41363040. Its totient is φ = 10378368.

The previous prime is 21403013. The next prime is 21403033. The reversal of 21403016 is 61030412.

It is a junction number, because it is equal to n+sod(n) for n = 21402985 and 21403003.

It is not an unprimeable number, because it can be changed into a prime (21403013) 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, 38855 + ... + 39401.

It is an arithmetic number, because the mean of its divisors is an integer number (1292595).

Almost surely, 2^21403016 is an apocalyptic number.

It is an amenable number.

21403016 is a deficient number, since it is larger than the sum of its proper divisors (19960024).

21403016 is a wasteful number, since it uses less digits than its factorization.

21403016 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 693 (or 689 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 17.

The square root of 21403016 is about 4626.3393736301. The cubic root of 21403016 is about 277.6461519437.

Adding to 21403016 its reverse (61030412), we get a palindrome (82433428).

The spelling of 21403016 in words is "twenty-one million, four hundred three thousand, sixteen".