70657 has 2 divisors, whose sum is σ = 70658. Its totient is φ = 70656.

The previous prime is 70639. The next prime is 70663. The reversal of 70657 is 75607.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 69696 + 961 = 264^2 + 31^2 .

It is a cyclic number.

It is not a de Polignac number, because 70657 - 2⁷ = 70529 is a prime.

70657 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (70607) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35328 + 35329.

It is an arithmetic number, because the mean of its divisors is an integer number (35329).

It is a Proth number, since it is equal to 69 ⋅ 2¹⁰ + 1 and 69 < 2¹⁰.

2⁷⁰⁶⁵⁷ is an apocalyptic number.

It is an amenable number.

70657 is a deficient number, since it is larger than the sum of its proper divisors (1).

70657 is an equidigital number, since it uses as much as digits as its factorization.

70657 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1470, while the sum is 25.

The square root of 70657 is about 265.8138446357. The cubic root of 70657 is about 41.3413890531.

Adding to 70657 its product of nonzero digits (1470), we get a palindrome (72127).

Subtracting 70657 from its reverse (75607), we obtain a triangular number (4950 = T₉₉).

It can be divided in two parts, 7065 and 7, that multiplied together give a triangular number (49455 = T₃₁₄).

The spelling of 70657 in words is "seventy thousand, six hundred fifty-seven".