61323061981 has 2 divisors, whose sum is σ = 61323061982. Its totient is φ = 61323061980.

The previous prime is 61323061973. The next prime is 61323062051. The reversal of 61323061981 is 18916032316.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 55350090756 + 5972971225 = 235266^2 + 77285^2 .

It is a cyclic number.

It is not a de Polignac number, because 61323061981 - 2³ = 61323061973 is a prime.

It is a super-2 number, since 2×61323061981² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61323061901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30661530990 + 30661530991.

It is an arithmetic number, because the mean of its divisors is an integer number (30661530991).

Almost surely, 2^61323061981 is an apocalyptic number.

It is an amenable number.

61323061981 is a deficient number, since it is larger than the sum of its proper divisors (1).

61323061981 is an equidigital number, since it uses as much as digits as its factorization.

61323061981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 46656, while the sum is 40.

The spelling of 61323061981 in words is "sixty-one billion, three hundred twenty-three million, sixty-one thousand, nine hundred eighty-one".