21273669387 has 8 divisors (see below), whose sum is σ = 31516547280. Its totient is φ = 14182446240.

The previous prime is 21273669383. The next prime is 21273669397. The reversal of 21273669387 is 78396637212.

It is not a de Polignac number, because 21273669387 - 2² = 21273669383 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21273669383) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 393956814 + ... + 393956867.

It is an arithmetic number, because the mean of its divisors is an integer number (3939568410).

Almost surely, 2^21273669387 is an apocalyptic number.

21273669387 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

21273669387 is a deficient number, since it is larger than the sum of its proper divisors (10242877893).

21273669387 is an equidigital number, since it uses as much as digits as its factorization.

21273669387 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 787913690 (or 787913684 counting only the distinct ones).

The product of its digits is 4572288, while the sum is 54.

The spelling of 21273669387 in words is "twenty-one billion, two hundred seventy-three million, six hundred sixty-nine thousand, three hundred eighty-seven".