1978567061 has 2 divisors, whose sum is σ = 1978567062. Its totient is φ = 1978567060.

The previous prime is 1978567051. The next prime is 1978567081. The reversal of 1978567061 is 1607658791.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1647872836 + 330694225 = 40594^2 + 18185^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1978567061 is a prime.

It is a super-3 number, since 3×1978567061³ (a number of 29 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1978567001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 989283530 + 989283531.

It is an arithmetic number, because the mean of its divisors is an integer number (989283531).

Almost surely, 2^1978567061 is an apocalyptic number.

It is an amenable number.

1978567061 is a deficient number, since it is larger than the sum of its proper divisors (1).

1978567061 is an equidigital number, since it uses as much as digits as its factorization.

1978567061 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 635040, while the sum is 50.

The square root of 1978567061 is about 44481.0865537253. The cubic root of 1978567061 is about 1255.4042413488.

The spelling of 1978567061 in words is "one billion, nine hundred seventy-eight million, five hundred sixty-seven thousand, sixty-one".