1620506 has 4 divisors (see below), whose sum is σ = 2430762. Its totient is φ = 810252.

The previous prime is 1620497. The next prime is 1620517. The reversal of 1620506 is 6050261.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 6050261 = 7 ⋅864323.

It can be written as a sum of positive squares in only one way, i.e., 1229881 + 390625 = 1109^2 + 625^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 405125 + ... + 405128.

2^1620506 is an apocalyptic number.

1620506 is a deficient number, since it is larger than the sum of its proper divisors (810256).

1620506 is an equidigital number, since it uses as much as digits as its factorization.

1620506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 810255.

The product of its (nonzero) digits is 360, while the sum is 20.

The square root of 1620506 is about 1272.9909661895. The cubic root of 1620506 is about 117.4582558821.

Adding to 1620506 its reverse (6050261), we get a palindrome (7670767).

The spelling of 1620506 in words is "one million, six hundred twenty thousand, five hundred six".