1620670717 has 4 divisors (see below), whose sum is σ = 1629156096. Its totient is φ = 1612185340.

The previous prime is 1620670703. The next prime is 1620670739. The reversal of 1620670717 is 7170760261.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 7170760261 = 7 ⋅1024394323.

It is a cyclic number.

It is not a de Polignac number, because 1620670717 - 2⁷ = 1620670589 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 (1620677717) 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, 4242403 + ... + 4242784.

It is an arithmetic number, because the mean of its divisors is an integer number (407289024).

Almost surely, 2^1620670717 is an apocalyptic number.

It is an amenable number.

1620670717 is a deficient number, since it is larger than the sum of its proper divisors (8485379).

1620670717 is an equidigital number, since it uses as much as digits as its factorization.

1620670717 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8485378.

The product of its (nonzero) digits is 24696, while the sum is 37.

The square root of 1620670717 is about 40257.5547816804. The cubic root of 1620670717 is about 1174.6223544486.

The spelling of 1620670717 in words is "one billion, six hundred twenty million, six hundred seventy thousand, seven hundred seventeen".