21147397916 has 12 divisors (see below), whose sum is σ = 37009022232. Its totient is φ = 10573391568.

The previous prime is 21147397897. The next prime is 21147397919. The reversal of 21147397916 is 61979374112.

It is a super-2 number, since 2×21147397916² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21147397919) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 157031 + ... + 258753.

It is an arithmetic number, because the mean of its divisors is an integer number (3084085186).

Almost surely, 2^21147397916 is an apocalyptic number.

It is an amenable number.

21147397916 is a deficient number, since it is larger than the sum of its proper divisors (15861624316).

21147397916 is a wasteful number, since it uses less digits than its factorization.

21147397916 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 153700 (or 153698 counting only the distinct ones).

The product of its digits is 571536, while the sum is 50.

The spelling of 21147397916 in words is "twenty-one billion, one hundred forty-seven million, three hundred ninety-seven thousand, nine hundred sixteen".