21421330344 has 24 divisors (see below), whose sum is σ = 58016103210. Its totient is φ = 7140443424.

The previous prime is 21421330319. The next prime is 21421330349. The reversal of 21421330344 is 44303312412.

It can be written as a sum of positive squares in only one way, i.e., 19171725444 + 2249604900 = 138462^2 + 47430^2 .

It is a tau number, because it is divible by the number of its divisors (24).

It is not an unprimeable number, because it can be changed into a prime (21421330349) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 148759167 + ... + 148759310.

Almost surely, 2^21421330344 is an apocalyptic number.

21421330344 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21421330344 is an abundant number, since it is smaller than the sum of its proper divisors (36594772866).

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

21421330344 is a wasteful number, since it uses less digits than its factorization.

21421330344 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 297518489 (or 297518482 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 27.

Adding to 21421330344 its reverse (44303312412), we get a palindrome (65724642756).

The spelling of 21421330344 in words is "twenty-one billion, four hundred twenty-one million, three hundred thirty thousand, three hundred forty-four".