61061200021 has 4 divisors (see below), whose sum is σ = 61068178444. Its totient is φ = 61054221600.

The previous prime is 61061200003. The next prime is 61061200033. The reversal of 61061200021 is 12000216016.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 8356519396 + 52704680625 = 91414^2 + 229575^2 .

It is a cyclic number.

It is not a de Polignac number, because 61061200021 - 2¹⁹ = 61060675733 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61061204021) 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, 3476070 + ... + 3493591.

It is an arithmetic number, because the mean of its divisors is an integer number (15267044611).

Almost surely, 2^61061200021 is an apocalyptic number.

It is an amenable number.

61061200021 is a deficient number, since it is larger than the sum of its proper divisors (6978423).

61061200021 is an equidigital number, since it uses as much as digits as its factorization.

61061200021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6978422.

The product of its (nonzero) digits is 144, while the sum is 19.

Adding to 61061200021 its reverse (12000216016), we get a palindrome (73061416037).

The spelling of 61061200021 in words is "sixty-one billion, sixty-one million, two hundred thousand, twenty-one".