21124221270 has 64 divisors (see below), whose sum is σ = 51349503744. Its totient is φ = 5560859520.

The previous prime is 21124221179. The next prime is 21124221271. The reversal of 21124221270 is 7212242112.

It is a self number, because there is not a number n which added to its sum of digits gives 21124221270.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21124221271) 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, 4213065 + ... + 4218075.

It is an arithmetic number, because the mean of its divisors is an integer number (802335996).

Almost surely, 2^21124221270 is an apocalyptic number.

21124221270 is an abundant number, since it is smaller than the sum of its proper divisors (30225282474).

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

21124221270 is a wasteful number, since it uses less digits than its factorization.

21124221270 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6797.

The product of its (nonzero) digits is 896, while the sum is 24.

Adding to 21124221270 its reverse (7212242112), we get a palindrome (28336463382).

The spelling of 21124221270 in words is "twenty-one billion, one hundred twenty-four million, two hundred twenty-one thousand, two hundred seventy".