70561 has 4 divisors (see below), whose sum is σ = 72324. Its totient is φ = 68800.

The previous prime is 70549. The next prime is 70571. The reversal of 70561 is 16507.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 16507 = 17 ⋅971.

It can be written as a sum of positive squares in 2 ways, for example, as 24336 + 46225 = 156^2 + 215^2 .

It is a cyclic number.

It is not a de Polignac number, because 70561 - 2⁵ = 70529 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (70501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 820 + ... + 901.

It is an arithmetic number, because the mean of its divisors is an integer number (18081).

2⁷⁰⁵⁶¹ is an apocalyptic number.

It is an amenable number.

70561 is a deficient number, since it is larger than the sum of its proper divisors (1763).

70561 is a wasteful number, since it uses less digits than its factorization.

70561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1762.

The product of its (nonzero) digits is 210, while the sum is 19.

The square root of 70561 is about 265.6332057556. The cubic root of 70561 is about 41.3226573769.

The spelling of 70561 in words is "seventy thousand, five hundred sixty-one".