20051213041661 has 4 divisors (see below), whose sum is σ = 20333624493024. Its totient is φ = 19768801590300.

The previous prime is 20051213041627. The next prime is 20051213041679. The reversal of 20051213041661 is 16614031215002.

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 20051213041661 - 2⁶ = 20051213041597 is a prime.

It is a super-2 number, since 2×20051213041661² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20051213041621) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 141205725575 + ... + 141205725716.

It is an arithmetic number, because the mean of its divisors is an integer number (5083406123256).

Almost surely, 2^{20051213041661} is an apocalyptic number.

It is an amenable number.

20051213041661 is a deficient number, since it is larger than the sum of its proper divisors (282411451363).

20051213041661 is an equidigital number, since it uses as much as digits as its factorization.

20051213041661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 282411451362.

The product of its (nonzero) digits is 8640, while the sum is 32.

Adding to 20051213041661 its reverse (16614031215002), we get a palindrome (36665244256663).

The spelling of 20051213041661 in words is "twenty trillion, fifty-one billion, two hundred thirteen million, forty-one thousand, six hundred sixty-one".