67819561 has 2 divisors, whose sum is σ = 67819562. Its totient is φ = 67819560.

The previous prime is 67819553. The next prime is 67819597. The reversal of 67819561 is 16591876.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 55875625 + 11943936 = 7475^2 + 3456^2 .

It is a cyclic number.

It is not a de Polignac number, because 67819561 - 2³ = 67819553 is a prime.

It is not a weakly prime, because it can be changed into another prime (67811561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33909780 + 33909781.

It is an arithmetic number, because the mean of its divisors is an integer number (33909781).

Almost surely, 2^67819561 is an apocalyptic number.

It is an amenable number.

67819561 is a deficient number, since it is larger than the sum of its proper divisors (1).

67819561 is an equidigital number, since it uses as much as digits as its factorization.

67819561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 90720, while the sum is 43.

The square root of 67819561 is about 8235.2632623372. The cubic root of 67819561 is about 407.8041659977.

The spelling of 67819561 in words is "sixty-seven million, eight hundred nineteen thousand, five hundred sixty-one".