21002084621 has 8 divisors (see below), whose sum is σ = 24006925824. Its totient is φ = 17998379280.

The previous prime is 21002084617. The next prime is 21002084629. The reversal of 21002084621 is 12648020012.

It is a happy number.

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

It is not a de Polignac number, because 21002084621 - 2² = 21002084617 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21002084629) 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, 243965 + ... + 318626.

It is an arithmetic number, because the mean of its divisors is an integer number (3000865728).

Almost surely, 2^21002084621 is an apocalyptic number.

It is an amenable number.

21002084621 is a deficient number, since it is larger than the sum of its proper divisors (3004841203).

21002084621 is an equidigital number, since it uses as much as digits as its factorization.

21002084621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 567931.

The product of its (nonzero) digits is 1536, while the sum is 26.

The spelling of 21002084621 in words is "twenty-one billion, two million, eighty-four thousand, six hundred twenty-one".