21253240162 has 16 divisors (see below), whose sum is σ = 39746319552. Its totient is φ = 8280483120.

The previous prime is 21253240147. The next prime is 21253240163. The reversal of 21253240162 is 26104235212.

It is a self number, because there is not a number n which added to its sum of digits gives 21253240162.

It is not an unprimeable number, because it can be changed into a prime (21253240163) 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, 69003873 + ... + 69004180.

It is an arithmetic number, because the mean of its divisors is an integer number (2484144972).

Almost surely, 2^21253240162 is an apocalyptic number.

21253240162 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21253240162 is a deficient number, since it is larger than the sum of its proper divisors (18493079390).

21253240162 is a wasteful number, since it uses less digits than its factorization.

21253240162 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 138008073.

The product of its (nonzero) digits is 5760, while the sum is 28.

Adding to 21253240162 its reverse (26104235212), we get a palindrome (47357475374).

The spelling of 21253240162 in words is "twenty-one billion, two hundred fifty-three million, two hundred forty thousand, one hundred sixty-two".