21403020210 has 256 divisors, whose sum is σ = 61961034240. Its totient is φ = 4690682880.

The previous prime is 21403020209. The next prime is 21403020211. The reversal of 21403020210 is 1202030412.

It is an interprime number because it is at equal distance from previous prime (21403020209) and next prime (21403020211).

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 21403020210.

It is not an unprimeable number, because it can be changed into a prime (21403020211) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 38425252 + ... + 38425808.

It is an arithmetic number, because the mean of its divisors is an integer number (242035290).

Almost surely, 2^21403020210 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21403020210, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30980517120).

21403020210 is an abundant number, since it is smaller than the sum of its proper divisors (40558014030).

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

21403020210 is a wasteful number, since it uses less digits than its factorization.

21403020210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 670 (or 644 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 15.

Adding to 21403020210 its reverse (1202030412), we get a palindrome (22605050622).

The spelling of 21403020210 in words is "twenty-one billion, four hundred three million, twenty thousand, two hundred ten".