70667561 has 2 divisors, whose sum is σ = 70667562. Its totient is φ = 70667560.

The previous prime is 70667551. The next prime is 70667563. The reversal of 70667561 is 16576607.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 45225625 + 25441936 = 6725^2 + 5044^2 .

It is a cyclic number.

It is not a de Polignac number, because 70667561 - 2²² = 66473257 is a prime.

Together with 70667563, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (70667563) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35333780 + 35333781.

It is an arithmetic number, because the mean of its divisors is an integer number (35333781).

Almost surely, 2^70667561 is an apocalyptic number.

It is an amenable number.

70667561 is a deficient number, since it is larger than the sum of its proper divisors (1).

70667561 is an equidigital number, since it uses as much as digits as its factorization.

70667561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 52920, while the sum is 38.

The square root of 70667561 is about 8406.4000023791. The cubic root of 70667561 is about 413.4344869640.

The spelling of 70667561 in words is "seventy million, six hundred sixty-seven thousand, five hundred sixty-one".