21001442122 has 16 divisors (see below), whose sum is σ = 31794647040. Its totient is φ = 10403458128.

The previous prime is 21001442107. The next prime is 21001442123. The reversal of 21001442122 is 22124410012.

It is a self number, because there is not a number n which added to its sum of digits gives 21001442122.

It is not an unprimeable number, because it can be changed into a prime (21001442123) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 125128 + ... + 240124.

It is an arithmetic number, because the mean of its divisors is an integer number (1987165440).

Almost surely, 2^21001442122 is an apocalyptic number.

21001442122 is a deficient number, since it is larger than the sum of its proper divisors (10793204918).

21001442122 is a wasteful number, since it uses less digits than its factorization.

21001442122 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 115845.

The product of its (nonzero) digits is 256, while the sum is 19.

Adding to 21001442122 its reverse (22124410012), we get a palindrome (43125852134).

The spelling of 21001442122 in words is "twenty-one billion, one million, four hundred forty-two thousand, one hundred twenty-two".