21144004002 has 48 divisors (see below), whose sum is σ = 50079586752. Its totient is φ = 6394088160.

The previous prime is 21144004001. The next prime is 21144004003. The reversal of 21144004002 is 20040044112.

It is an interprime number because it is at equal distance from previous prime (21144004001) and next prime (21144004003).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (21144004001) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 13213 + ... + 206064.

It is an arithmetic number, because the mean of its divisors is an integer number (1043324724).

Almost surely, 2^21144004002 is an apocalyptic number.

21144004002 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21144004002 is an abundant number, since it is smaller than the sum of its proper divisors (28935582750).

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

21144004002 is a wasteful number, since it uses less digits than its factorization.

21144004002 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 219783 (or 219780 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 18.

Adding to 21144004002 its reverse (20040044112), we get a palindrome (41184048114).

The spelling of 21144004002 in words is "twenty-one billion, one hundred forty-four million, four thousand, two".