21400321144 has 16 divisors (see below), whose sum is σ = 40167111600. Its totient is φ = 10689091392.

The previous prime is 21400321097. The next prime is 21400321147. The reversal of 21400321144 is 44112300412.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21400321147) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1375429 + ... + 1390900.

It is an arithmetic number, because the mean of its divisors is an integer number (2510444475).

Almost surely, 2^21400321144 is an apocalyptic number.

It is an amenable number.

21400321144 is a deficient number, since it is larger than the sum of its proper divisors (18766790456).

21400321144 is a wasteful number, since it uses less digits than its factorization.

21400321144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2767302 (or 2767298 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 22.

Adding to 21400321144 its reverse (44112300412), we get a palindrome (65512621556).

The spelling of 21400321144 in words is "twenty-one billion, four hundred million, three hundred twenty-one thousand, one hundred forty-four".