21011012274 has 64 divisors (see below), whose sum is σ = 49481591040. Its totient is φ = 5822791680.

The previous prime is 21011012273. The next prime is 21011012291. The reversal of 21011012274 is 47221011012.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a self number, because there is not a number n which added to its sum of digits gives 21011012274.

It is not an unprimeable number, because it can be changed into a prime (21011012273) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 262642 + ... + 333170.

It is an arithmetic number, because the mean of its divisors is an integer number (773149860).

Almost surely, 2^21011012274 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21011012274, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24740795520).

21011012274 is an abundant number, since it is smaller than the sum of its proper divisors (28470578766).

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

21011012274 is a wasteful number, since it uses less digits than its factorization.

21011012274 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70755.

The product of its (nonzero) digits is 224, while the sum is 21.

Adding to 21011012274 its reverse (47221011012), we get a palindrome (68232023286).

The spelling of 21011012274 in words is "twenty-one billion, eleven million, twelve thousand, two hundred seventy-four".