21231645337 has 8 divisors (see below), whose sum is σ = 24500318336. Its totient is φ = 18021867552.

The previous prime is 21231645319. The next prime is 21231645349. The reversal of 21231645337 is 73354613212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21231645337 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21231645296 and 21231645305.

It is not an unprimeable number, because it can be changed into a prime (21231645307) 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, 14723028 + ... + 14724469.

It is an arithmetic number, because the mean of its divisors is an integer number (3062539792).

Almost surely, 2^21231645337 is an apocalyptic number.

It is an amenable number.

21231645337 is a deficient number, since it is larger than the sum of its proper divisors (3268672999).

21231645337 is a wasteful number, since it uses less digits than its factorization.

21231645337 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29447607.

The product of its digits is 90720, while the sum is 37.

The spelling of 21231645337 in words is "twenty-one billion, two hundred thirty-one million, six hundred forty-five thousand, three hundred thirty-seven".