21278421351 has 12 divisors (see below), whose sum is σ = 33529633800. Its totient is φ = 12896012880.

The previous prime is 21278421349. The next prime is 21278421419. The reversal of 21278421351 is 15312487212.

21278421351 is a `hidden beast` number, since 212 + 78 + 4 + 21 + 351 = 666.

It is not a de Polignac number, because 21278421351 - 2¹ = 21278421349 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21278421341) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 107466676 + ... + 107466873.

It is an arithmetic number, because the mean of its divisors is an integer number (2794136150).

Almost surely, 2^21278421351 is an apocalyptic number.

21278421351 is a deficient number, since it is larger than the sum of its proper divisors (12251212449).

21278421351 is a wasteful number, since it uses less digits than its factorization.

21278421351 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 214933566 (or 214933563 counting only the distinct ones).

The product of its digits is 26880, while the sum is 36.

The spelling of 21278421351 in words is "twenty-one billion, two hundred seventy-eight million, four hundred twenty-one thousand, three hundred fifty-one".