21397735012 has 6 divisors (see below), whose sum is σ = 37446036278. Its totient is φ = 10698867504.

The previous prime is 21397734983. The next prime is 21397735019. The reversal of 21397735012 is 21053779312.

It can be written as a sum of positive squares in only one way, i.e., 17380203556 + 4017531456 = 131834^2 + 63384^2 .

It is not an unprimeable number, because it can be changed into a prime (21397735019) 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 as a sum of consecutive naturals, namely, 2674716873 + ... + 2674716880.

Almost surely, 2^21397735012 is an apocalyptic number.

It is an amenable number.

21397735012 is a deficient number, since it is larger than the sum of its proper divisors (16048301266).

21397735012 is a wasteful number, since it uses less digits than its factorization.

21397735012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5349433757 (or 5349433755 counting only the distinct ones).

The product of its (nonzero) digits is 79380, while the sum is 40.

The spelling of 21397735012 in words is "twenty-one billion, three hundred ninety-seven million, seven hundred thirty-five thousand, twelve".