61000665105521 has 2 divisors, whose sum is σ = 61000665105522. Its totient is φ = 61000665105520.

The previous prime is 61000665105467. The next prime is 61000665105551. The reversal of 61000665105521 is 12550156600016.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 59513679969121 + 1486985136400 = 7714511^2 + 1219420^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61000665105521 is a prime.

It is a super-2 number, since 2×61000665105521² (a number of 28 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (61000665105551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30500332552760 + 30500332552761.

It is an arithmetic number, because the mean of its divisors is an integer number (30500332552761).

Almost surely, 2^{61000665105521} is an apocalyptic number.

It is an amenable number.

61000665105521 is a deficient number, since it is larger than the sum of its proper divisors (1).

61000665105521 is an equidigital number, since it uses as much as digits as its factorization.

61000665105521 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 54000, while the sum is 38.

The spelling of 61000665105521 in words is "sixty-one trillion, six hundred sixty-five million, one hundred five thousand, five hundred twenty-one".