21213244430 has 64 divisors (see below), whose sum is σ = 43957444608. Its totient is φ = 7220119680.

The previous prime is 21213244427. The next prime is 21213244433. The reversal of 21213244430 is 3444231212.

It is an interprime number because it is at equal distance from previous prime (21213244427) and next prime (21213244433).

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21213244430.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21213244433) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 14906699 + ... + 14908121.

It is an arithmetic number, because the mean of its divisors is an integer number (686835072).

Almost surely, 2^21213244430 is an apocalyptic number.

21213244430 is an abundant number, since it is smaller than the sum of its proper divisors (22744200178).

21213244430 is a wasteful number, since it uses less digits than its factorization.

21213244430 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2841.

The product of its (nonzero) digits is 4608, while the sum is 26.

Adding to 21213244430 its reverse (3444231212), we get a palindrome (24657475642).

The spelling of 21213244430 in words is "twenty-one billion, two hundred thirteen million, two hundred forty-four thousand, four hundred thirty".