21661045252033 has 8 divisors (see below), whose sum is σ = 23720079974976. Its totient is φ = 19616985327600.

The previous prime is 21661045251889. The next prime is 21661045252051. The reversal of 21661045252033 is 33025254016612.

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-21661045252033 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21661045252633) 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, 3743696598 + ... + 3743702383.

It is an arithmetic number, because the mean of its divisors is an integer number (2965009996872).

Almost surely, 2^{21661045252033} is an apocalyptic number.

It is an amenable number.

21661045252033 is a deficient number, since it is larger than the sum of its proper divisors (2059034722943).

21661045252033 is a wasteful number, since it uses less digits than its factorization.

21661045252033 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7487399255.

The product of its (nonzero) digits is 259200, while the sum is 40.

Adding to 21661045252033 its reverse (33025254016612), we get a palindrome (54686299268645).

The spelling of 21661045252033 in words is "twenty-one trillion, six hundred sixty-one billion, forty-five million, two hundred fifty-two thousand, thirty-three".