21012002321 has 8 divisors (see below), whose sum is σ = 22127614080. Its totient is φ = 19897362288.

The previous prime is 21012002303. The next prime is 21012002339. The reversal of 21012002321 is 12320021012.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21012002303) and next prime (21012002339).

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21012002321 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21012002296 and 21012002305.

It is not an unprimeable number, because it can be changed into a prime (21012002351) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 198326 + ... + 285231.

It is an arithmetic number, because the mean of its divisors is an integer number (2765951760).

Almost surely, 2^21012002321 is an apocalyptic number.

It is an amenable number.

21012002321 is a deficient number, since it is larger than the sum of its proper divisors (1115611759).

21012002321 is a wasteful number, since it uses less digits than its factorization.

21012002321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 485863.

The product of its (nonzero) digits is 48, while the sum is 14.

Adding to 21012002321 its reverse (12320021012), we get a palindrome (33332023333).

The spelling of 21012002321 in words is "twenty-one billion, twelve million, two thousand, three hundred twenty-one".