67406561 has 8 divisors (see below), whose sum is σ = 68371464. Its totient is φ = 66447360.

The previous prime is 67406543. The next prime is 67406569. The reversal of 67406561 is 16560476.

It can be written as a sum of positive squares in 4 ways, for example, as 20566225 + 46840336 = 4535^2 + 6844^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 67406561 - 2¹⁰ = 67405537 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (67406569) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 26021 + ... + 28493.

It is an arithmetic number, because the mean of its divisors is an integer number (8546433).

Almost surely, 2^67406561 is an apocalyptic number.

It is an amenable number.

67406561 is a deficient number, since it is larger than the sum of its proper divisors (964903).

67406561 is a wasteful number, since it uses less digits than its factorization.

67406561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2851.

The product of its (nonzero) digits is 30240, while the sum is 35.

The square root of 67406561 is about 8210.1498768293. The cubic root of 67406561 is about 406.9746798295.

The spelling of 67406561 in words is "sixty-seven million, four hundred six thousand, five hundred sixty-one".