21646002 has 16 divisors (see below), whose sum is σ = 49476672. Its totient is φ = 6184560.

The previous prime is 21645937. The next prime is 21646003. The reversal of 21646002 is 20064612.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a self number, because there is not a number n which added to its sum of digits gives 21646002.

It is not an unprimeable number, because it can be changed into a prime (21646003) 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 7 ways as a sum of consecutive naturals, for example, 257649 + ... + 257732.

It is an arithmetic number, because the mean of its divisors is an integer number (3092292).

Almost surely, 2^21646002 is an apocalyptic number.

21646002 is an abundant number, since it is smaller than the sum of its proper divisors (27830670).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21646002 is a wasteful number, since it uses less digits than its factorization.

21646002 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 515393.

The product of its (nonzero) digits is 576, while the sum is 21.

The square root of 21646002 is about 4652.5264104570. The cubic root of 21646002 is about 278.6928957274.

The spelling of 21646002 in words is "twenty-one million, six hundred forty-six thousand, two".