1620417 has 4 divisors (see below), whose sum is σ = 2160560. Its totient is φ = 1080276.

The previous prime is 1620413. The next prime is 1620431. The reversal of 1620417 is 7140261.

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.

It is not a de Polignac number, because 1620417 - 2² = 1620413 is a prime.

It is a D-number.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1620393 and 1620402.

It is not an unprimeable number, because it can be changed into a prime (1620413) 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, 270067 + ... + 270072.

It is an arithmetic number, because the mean of its divisors is an integer number (540140).

2^1620417 is an apocalyptic number.

It is an amenable number.

1620417 is a deficient number, since it is larger than the sum of its proper divisors (540143).

1620417 is an equidigital number, since it uses as much as digits as its factorization.

1620417 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 540142.

The product of its (nonzero) digits is 336, while the sum is 21.

The square root of 1620417 is about 1272.9560086664. The cubic root of 1620417 is about 117.4561055298.

Adding to 1620417 its reverse (7140261), we get a palindrome (8760678).

The spelling of 1620417 in words is "one million, six hundred twenty thousand, four hundred seventeen".