21403412 has 12 divisors (see below), whose sum is σ = 37491636. Its totient is φ = 10691520.

The previous prime is 21403399. The next prime is 21403433. The reversal of 21403412 is 21430412.

It can be written as a sum of positive squares in 2 ways, for example, as 2775556 + 18627856 = 1666^2 + 4316^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4118 + ... + 7730.

It is an arithmetic number, because the mean of its divisors is an integer number (3124303).

Almost surely, 2^21403412 is an apocalyptic number.

It is an amenable number.

21403412 is a deficient number, since it is larger than the sum of its proper divisors (16088224).

21403412 is a wasteful number, since it uses less digits than its factorization.

21403412 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5098 (or 5096 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 17.

The square root of 21403412 is about 4626.3821718488. The cubic root of 21403412 is about 277.6478642756.

Adding to 21403412 its reverse (21430412), we get a palindrome (42833824).

Subtracting 21403412 from its reverse (21430412), we obtain a cube (27000 = 30³).

The spelling of 21403412 in words is "twenty-one million, four hundred three thousand, four hundred twelve".