67291561 has 2 divisors, whose sum is σ = 67291562. Its totient is φ = 67291560.

The previous prime is 67291547. The next prime is 67291577. The reversal of 67291561 is 16519276.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 55041561 + 12250000 = 7419^2 + 3500^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-67291561 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 67291561.

It is not a weakly prime, because it can be changed into another prime (67291501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33645780 + 33645781.

It is an arithmetic number, because the mean of its divisors is an integer number (33645781).

Almost surely, 2^67291561 is an apocalyptic number.

It is an amenable number.

67291561 is a deficient number, since it is larger than the sum of its proper divisors (1).

67291561 is an equidigital number, since it uses as much as digits as its factorization.

67291561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 22680, while the sum is 37.

The square root of 67291561 is about 8203.1433609318. The cubic root of 67291561 is about 406.7431062826.

The spelling of 67291561 in words is "sixty-seven million, two hundred ninety-one thousand, five hundred sixty-one".