67961561 has 4 divisors (see below), whose sum is σ = 68055012. Its totient is φ = 67868112.

The previous prime is 67961549. The next prime is 67961581. The reversal of 67961561 is 16516976.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 64561225 + 3400336 = 8035^2 + 1844^2 .

It is a cyclic number.

It is not a de Polignac number, because 67961561 - 2⁶ = 67961497 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (67961501) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 45626 + ... + 47091.

It is an arithmetic number, because the mean of its divisors is an integer number (17013753).

Almost surely, 2^67961561 is an apocalyptic number.

It is an amenable number.

67961561 is a deficient number, since it is larger than the sum of its proper divisors (93451).

67961561 is an equidigital number, since it uses as much as digits as its factorization.

67961561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 93450.

The product of its digits is 68040, while the sum is 41.

The square root of 67961561 is about 8243.8802150444. The cubic root of 67961561 is about 408.0885865090.

The spelling of 67961561 in words is "sixty-seven million, nine hundred sixty-one thousand, five hundred sixty-one".