21065402 has 8 divisors (see below), whose sum is σ = 31687200. Its totient is φ = 10503004.

The previous prime is 21065381. The next prime is 21065413. The reversal of 21065402 is 20456012.

It is a happy number.

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

It is a super-2 number, since 2×21065402² = 887502322843208, which contains 22 as substring.

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, 13952 + ... + 15387.

It is an arithmetic number, because the mean of its divisors is an integer number (3960900).

Almost surely, 2^21065402 is an apocalyptic number.

21065402 is a deficient number, since it is larger than the sum of its proper divisors (10621798).

21065402 is a wasteful number, since it uses less digits than its factorization.

21065402 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29700.

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 21065402 is about 4589.7060908080. The cubic root of 21065402 is about 276.1785321836.

The spelling of 21065402 in words is "twenty-one million, sixty-five thousand, four hundred two".