21153751237 has 4 divisors (see below), whose sum is σ = 21421520320. Its totient is φ = 20885982156.

The previous prime is 21153751207. The next prime is 21153751249. The reversal of 21153751237 is 73215735112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21153751237 - 2¹⁹ = 21153226949 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21153751196 and 21153751205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21153751207) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 133884423 + ... + 133884580.

It is an arithmetic number, because the mean of its divisors is an integer number (5355380080).

Almost surely, 2^21153751237 is an apocalyptic number.

It is an amenable number.

21153751237 is a deficient number, since it is larger than the sum of its proper divisors (267769083).

21153751237 is an equidigital number, since it uses as much as digits as its factorization.

21153751237 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 267769082.

The product of its digits is 44100, while the sum is 37.

The spelling of 21153751237 in words is "twenty-one billion, one hundred fifty-three million, seven hundred fifty-one thousand, two hundred thirty-seven".