61400818993 has 2 divisors, whose sum is σ = 61400818994. Its totient is φ = 61400818992.

The previous prime is 61400818981. The next prime is 61400819023. The reversal of 61400818993 is 39981800416.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 55914750369 + 5486068624 = 236463^2 + 74068^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61400818993 is a prime.

It is a super-2 number, since 2×61400818993² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (61400918993) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30700409496 + 30700409497.

It is an arithmetic number, because the mean of its divisors is an integer number (30700409497).

Almost surely, 2^61400818993 is an apocalyptic number.

It is an amenable number.

61400818993 is a deficient number, since it is larger than the sum of its proper divisors (1).

61400818993 is an equidigital number, since it uses as much as digits as its factorization.

61400818993 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 373248, while the sum is 49.

The spelling of 61400818993 in words is "sixty-one billion, four hundred million, eight hundred eighteen thousand, nine hundred ninety-three".