670887521 has 4 divisors (see below), whose sum is σ = 672577812. Its totient is φ = 669197232.

The previous prime is 670887499. The next prime is 670887557. The reversal of 670887521 is 125788076.

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 194993296 + 475894225 = 13964^2 + 21815^2 .

It is a cyclic number.

It is not a de Polignac number, because 670887521 - 2⁶ = 670887457 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (670887571) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 844550 + ... + 845343.

It is an arithmetic number, because the mean of its divisors is an integer number (168144453).

Almost surely, 2^670887521 is an apocalyptic number.

It is an amenable number.

670887521 is a deficient number, since it is larger than the sum of its proper divisors (1690291).

670887521 is a wasteful number, since it uses less digits than its factorization.

670887521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1690290.

The product of its (nonzero) digits is 188160, while the sum is 44.

The square root of 670887521 is about 25901.4965011676. The cubic root of 670887521 is about 875.4202154669.

The spelling of 670887521 in words is "six hundred seventy million, eight hundred eighty-seven thousand, five hundred twenty-one".