21210312030 has 32 divisors (see below), whose sum is σ = 52660087200. Its totient is φ = 5461045632.

The previous prime is 21210312023. The next prime is 21210312031. The reversal of 21210312030 is 3021301212.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21210312031) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12188965 + ... + 12190704.

It is an arithmetic number, because the mean of its divisors is an integer number (1645627725).

Almost surely, 2^21210312030 is an apocalyptic number.

21210312030 is an abundant number, since it is smaller than the sum of its proper divisors (31449775170).

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

21210312030 is a wasteful number, since it uses less digits than its factorization.

21210312030 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24379708.

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

Adding to 21210312030 its reverse (3021301212), we get a palindrome (24231613242).

The spelling of 21210312030 in words is "twenty-one billion, two hundred ten million, three hundred twelve thousand, thirty".