61121545021 has 2 divisors, whose sum is σ = 61121545022. Its totient is φ = 61121545020.

The previous prime is 61121544947. The next prime is 61121545039. The reversal of 61121545021 is 12054512116.

61121545021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 33593757796 + 27527787225 = 183286^2 + 165915^2 .

It is a cyclic number.

It is not a de Polignac number, because 61121545021 - 2¹¹ = 61121542973 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61121545081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30560772510 + 30560772511.

It is an arithmetic number, because the mean of its divisors is an integer number (30560772511).

Almost surely, 2^61121545021 is an apocalyptic number.

It is an amenable number.

61121545021 is a deficient number, since it is larger than the sum of its proper divisors (1).

61121545021 is an equidigital number, since it uses as much as digits as its factorization.

61121545021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2400, while the sum is 28.

The spelling of 61121545021 in words is "sixty-one billion, one hundred twenty-one million, five hundred forty-five thousand, twenty-one".