670655621 has 4 divisors (see below), whose sum is σ = 670751244. Its totient is φ = 670560000.

The previous prime is 670655567. The next prime is 670655633. The reversal of 670655621 is 126556076.

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 253924225 + 416731396 = 15935^2 + 20414^2 .

It is a cyclic number.

It is not a de Polignac number, because 670655621 - 2¹⁰ = 670654597 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (670655641) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 36380 + ... + 51621.

It is an arithmetic number, because the mean of its divisors is an integer number (167687811).

Almost surely, 2^670655621 is an apocalyptic number.

It is an amenable number.

670655621 is a deficient number, since it is larger than the sum of its proper divisors (95623).

670655621 is an equidigital number, since it uses as much as digits as its factorization.

670655621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 95622.

The product of its (nonzero) digits is 75600, while the sum is 38.

The square root of 670655621 is about 25897.0195389354. The cubic root of 670655621 is about 875.3193374821.

The spelling of 670655621 in words is "six hundred seventy million, six hundred fifty-five thousand, six hundred twenty-one".