6840279400561 has 2 divisors, whose sum is σ = 6840279400562. Its totient is φ = 6840279400560.

The previous prime is 6840279400523. The next prime is 6840279400571. The reversal of 6840279400561 is 1650049720486.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6836295266161 + 3984134400 = 2614631^2 + 63120^2 .

It is a cyclic number.

It is not a de Polignac number, because 6840279400561 - 2⁹ = 6840279400049 is a prime.

It is a super-2 number, since 2×6840279400561² (a number of 26 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 6840279400499 and 6840279400508.

It is not a weakly prime, because it can be changed into another prime (6840279400501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3420139700280 + 3420139700281.

It is an arithmetic number, because the mean of its divisors is an integer number (3420139700281).

Almost surely, 2^{6840279400561} is an apocalyptic number.

It is an amenable number.

6840279400561 is a deficient number, since it is larger than the sum of its proper divisors (1).

6840279400561 is an equidigital number, since it uses as much as digits as its factorization.

6840279400561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2903040, while the sum is 52.

The spelling of 6840279400561 in words is "six trillion, eight hundred forty billion, two hundred seventy-nine million, four hundred thousand, five hundred sixty-one".