67461781 has 2 divisors, whose sum is σ = 67461782. Its totient is φ = 67461780.

The previous prime is 67461749. The next prime is 67461787. The reversal of 67461781 is 18716476.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 35640900 + 31820881 = 5970^2 + 5641^2 .

It is a cyclic number.

It is not a de Polignac number, because 67461781 - 2⁵ = 67461749 is a prime.

It is a super-2 number, since 2×67461781² = 9102183791383922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (67461787) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33730890 + 33730891.

It is an arithmetic number, because the mean of its divisors is an integer number (33730891).

Almost surely, 2^67461781 is an apocalyptic number.

It is an amenable number.

67461781 is a deficient number, since it is larger than the sum of its proper divisors (1).

67461781 is an equidigital number, since it uses as much as digits as its factorization.

67461781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 56448, while the sum is 40.

The square root of 67461781 is about 8213.5120989745. The cubic root of 67461781 is about 407.0857818130.

The spelling of 67461781 in words is "sixty-seven million, four hundred sixty-one thousand, seven hundred eighty-one".