21278247000 has 64 divisors (see below), whose sum is σ = 66388140000. Its totient is φ = 5674198400.

The previous prime is 21278246989. The next prime is 21278247037. The reversal of 21278247000 is 74287212.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3543375 + ... + 3549374.

Almost surely, 2^21278247000 is an apocalyptic number.

21278247000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21278247000 is an abundant number, since it is smaller than the sum of its proper divisors (45109893000).

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

21278247000 is a wasteful number, since it uses less digits than its factorization.

21278247000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7092773 (or 7092759 counting only the distinct ones).

The product of its (nonzero) digits is 12544, while the sum is 33.

It can be divided in two parts, 21278 and 247000, that added together give a triangular number (268278 = T₇₃₂).

The spelling of 21278247000 in words is "twenty-one billion, two hundred seventy-eight million, two hundred forty-seven thousand".