21278634351 has 48 divisors (see below), whose sum is σ = 31404996000. Its totient is φ = 12805019136.

The previous prime is 21278634343. The next prime is 21278634359. The reversal of 21278634351 is 15343687212.

It is an interprime number because it is at equal distance from previous prime (21278634343) and next prime (21278634359).

It is not a de Polignac number, because 21278634351 - 2³ = 21278634343 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21278634359) 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 47 ways as a sum of consecutive naturals, for example, 9376845 + ... + 9379113.

It is an arithmetic number, because the mean of its divisors is an integer number (654270750).

Almost surely, 2^21278634351 is an apocalyptic number.

21278634351 is a deficient number, since it is larger than the sum of its proper divisors (10126361649).

21278634351 is a wasteful number, since it uses less digits than its factorization.

21278634351 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2700 (or 2687 counting only the distinct ones).

The product of its digits is 241920, while the sum is 42.

The spelling of 21278634351 in words is "twenty-one billion, two hundred seventy-eight million, six hundred thirty-four thousand, three hundred fifty-one".