21020325144 has 64 divisors (see below), whose sum is σ = 64677930240. Its totient is φ = 5543821440.

The previous prime is 21020325143. The next prime is 21020325149. The reversal of 21020325144 is 44152302012.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21020325143) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4810162 + ... + 4814529.

It is an arithmetic number, because the mean of its divisors is an integer number (1010592660).

Almost surely, 2^21020325144 is an apocalyptic number.

21020325144 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21020325144 is an abundant number, since it is smaller than the sum of its proper divisors (43657605096).

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

21020325144 is a wasteful number, since it uses less digits than its factorization.

21020325144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9624720 (or 9624716 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 24.

Adding to 21020325144 its reverse (44152302012), we get a palindrome (65172627156).

The spelling of 21020325144 in words is "twenty-one billion, twenty million, three hundred twenty-five thousand, one hundred forty-four".