670757921 has 4 divisors (see below), whose sum is σ = 673368132. Its totient is φ = 668147712.

The previous prime is 670757897. The next prime is 670757951. The reversal of 670757921 is 129757076.

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 630562321 + 40195600 = 25111^2 + 6340^2 .

It is a cyclic number.

It is not a de Polignac number, because 670757921 - 2¹⁴ = 670741537 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (670757951) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1304720 + ... + 1305233.

It is an arithmetic number, because the mean of its divisors is an integer number (168342033).

Almost surely, 2^670757921 is an apocalyptic number.

It is an amenable number.

670757921 is a deficient number, since it is larger than the sum of its proper divisors (2610211).

670757921 is a wasteful number, since it uses less digits than its factorization.

670757921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2610210.

The product of its (nonzero) digits is 185220, while the sum is 44.

The square root of 670757921 is about 25898.9945943853. The cubic root of 670757921 is about 875.3638415032.

The spelling of 670757921 in words is "six hundred seventy million, seven hundred fifty-seven thousand, nine hundred twenty-one".