21210130320 has 40 divisors (see below), whose sum is σ = 65751404736. Its totient is φ = 5656034688.

The previous prime is 21210130309. The next prime is 21210130321. The reversal of 21210130320 is 2303101212.

It is a tau number, because it is divible by the number of its divisors (40).

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 21210130320.

It is not an unprimeable number, because it can be changed into a prime (21210130321) 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, 44187532 + ... + 44188011.

Almost surely, 2^21210130320 is an apocalyptic number.

21210130320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21210130320 is an abundant number, since it is smaller than the sum of its proper divisors (44541274416).

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

21210130320 is a wasteful number, since it uses less digits than its factorization.

21210130320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 88375559 (or 88375553 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 15.

Adding to 21210130320 its reverse (2303101212), we get a palindrome (23513231532).

The spelling of 21210130320 in words is "twenty-one billion, two hundred ten million, one hundred thirty thousand, three hundred twenty".