21390002 has 8 divisors (see below), whose sum is σ = 32170800. Its totient is φ = 10666404.

The previous prime is 21389999. The next prime is 21390007. The reversal of 21390002 is 20009312.

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

It is not an unprimeable number, because it can be changed into a prime (21390007) by changing a digit.

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, 13352 + ... + 14867.

It is an arithmetic number, because the mean of its divisors is an integer number (4021350).

Almost surely, 2^21390002 is an apocalyptic number.

21390002 is a deficient number, since it is larger than the sum of its proper divisors (10780798).

21390002 is a wasteful number, since it uses less digits than its factorization.

21390002 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28600.

The product of its (nonzero) digits is 108, while the sum is 17.

The square root of 21390002 is about 4624.9326481582. The cubic root of 21390002 is about 277.5898667358.

Adding to 21390002 its reverse (20009312), we get a palindrome (41399314).

The spelling of 21390002 in words is "twenty-one million, three hundred ninety thousand, two".