21403370 has 8 divisors (see below), whose sum is σ = 38526084. Its totient is φ = 8561344.

The previous prime is 21403337. The next prime is 21403399. The reversal of 21403370 is 7330412.

It can be written as a sum of positive squares in 2 ways, for example, as 21353641 + 49729 = 4621^2 + 223^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1070159 + ... + 1070178.

Almost surely, 2^21403370 is an apocalyptic number.

21403370 is a deficient number, since it is larger than the sum of its proper divisors (17122714).

21403370 is a wasteful number, since it uses less digits than its factorization.

21403370 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2140344.

The product of its (nonzero) digits is 504, while the sum is 20.

The square root of 21403370 is about 4626.3776326625. The cubic root of 21403370 is about 277.6476826656.

Adding to 21403370 its reverse (7330412), we get a palindrome (28733782).

The spelling of 21403370 in words is "twenty-one million, four hundred three thousand, three hundred seventy".