21210300234 has 24 divisors (see below), whose sum is σ = 46585182852. Its totient is φ = 6973248960.

The previous prime is 21210300211. The next prime is 21210300239. The reversal of 21210300234 is 43200301212.

It can be written as a sum of positive squares in 2 ways, for example, as 18833445225 + 2376855009 = 137235^2 + 48753^2 .

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (21210300239) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8069577 + ... + 8072204.

Almost surely, 2^21210300234 is an apocalyptic number.

21210300234 is an abundant number, since it is smaller than the sum of its proper divisors (25374882618).

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

21210300234 is a wasteful number, since it uses less digits than its factorization.

21210300234 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16141862 (or 16141859 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 18.

Adding to 21210300234 its reverse (43200301212), we get a palindrome (64410601446).

The spelling of 21210300234 in words is "twenty-one billion, two hundred ten million, three hundred thousand, two hundred thirty-four".