21044661351 has 16 divisors (see below), whose sum is σ = 32519720448. Its totient is φ = 11856146400.

The previous prime is 21044661349. The next prime is 21044661373. The reversal of 21044661351 is 15316644012.

It is not a de Polignac number, because 21044661351 - 2¹ = 21044661349 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21044661311) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7055740 + ... + 7058721.

It is an arithmetic number, because the mean of its divisors is an integer number (2032482528).

Almost surely, 2^21044661351 is an apocalyptic number.

21044661351 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21044661351 is a deficient number, since it is larger than the sum of its proper divisors (11475059097).

21044661351 is a wasteful number, since it uses less digits than its factorization.

21044661351 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14114542.

The product of its (nonzero) digits is 17280, while the sum is 33.

The spelling of 21044661351 in words is "twenty-one billion, forty-four million, six hundred sixty-one thousand, three hundred fifty-one".