21403052 has 12 divisors (see below), whose sum is σ = 40860456. Its totient is φ = 9728640.

The previous prime is 21403049. The next prime is 21403061. The reversal of 21403052 is 25030412.

It is a self number, because there is not a number n which added to its sum of digits gives 21403052.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 243173 + ... + 243260.

It is an arithmetic number, because the mean of its divisors is an integer number (3405038).

Almost surely, 2^21403052 is an apocalyptic number.

21403052 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21403052 is a deficient number, since it is larger than the sum of its proper divisors (19457404).

21403052 is a wasteful number, since it uses less digits than its factorization.

21403052 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 486448 (or 486446 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 17.

The square root of 21403052 is about 4626.3432643936. The cubic root of 21403052 is about 277.6463076111.

Adding to 21403052 its reverse (25030412), we get a palindrome (46433464).

The spelling of 21403052 in words is "twenty-one million, four hundred three thousand, fifty-two".