21274720389 has 80 divisors (see below), whose sum is σ = 36045609600. Its totient is φ = 12406483584.

The previous prime is 21274720381. The next prime is 21274720403. The reversal of 21274720389 is 98302747212.

It is not a de Polignac number, because 21274720389 - 2³ = 21274720381 is a prime.

It is a super-2 number, since 2×21274720389² (a number of 21 digits) contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21274720381) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 2635842 + ... + 2643900.

It is an arithmetic number, because the mean of its divisors is an integer number (450570120).

Almost surely, 2^21274720389 is an apocalyptic number.

It is an amenable number.

21274720389 is a deficient number, since it is larger than the sum of its proper divisors (14770889211).

21274720389 is a wasteful number, since it uses less digits than its factorization.

21274720389 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8216 (or 8207 counting only the distinct ones).

The product of its (nonzero) digits is 338688, while the sum is 45.

The spelling of 21274720389 in words is "twenty-one billion, two hundred seventy-four million, seven hundred twenty thousand, three hundred eighty-nine".