21043221245 has 8 divisors (see below), whose sum is σ = 25276652640. Its totient is φ = 16818052240.

The previous prime is 21043221229. The next prime is 21043221263. The reversal of 21043221245 is 54212234012.

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

It is not a de Polignac number, because 21043221245 - 2⁴ = 21043221229 is a prime.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2059991 + ... + 2070180.

It is an arithmetic number, because the mean of its divisors is an integer number (3159581580).

Almost surely, 2^21043221245 is an apocalyptic number.

It is an amenable number.

21043221245 is a deficient number, since it is larger than the sum of its proper divisors (4233431395).

21043221245 is a wasteful number, since it uses less digits than its factorization.

21043221245 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4131195.

The product of its (nonzero) digits is 3840, while the sum is 26.

Adding to 21043221245 its reverse (54212234012), we get a palindrome (75255455257).

The spelling of 21043221245 in words is "twenty-one billion, forty-three million, two hundred twenty-one thousand, two hundred forty-five".