1620331 has 2 divisors, whose sum is σ = 1620332. Its totient is φ = 1620330.

The previous prime is 1620329. The next prime is 1620337. The reversal of 1620331 is 1330261.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1620331 - 2¹ = 1620329 is a prime.

It is a super-2 number, since 2×1620331² = 5250945099122, which contains 22 as substring.

Together with 1620329, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (1620337) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 810165 + 810166.

It is an arithmetic number, because the mean of its divisors is an integer number (810166).

2^1620331 is an apocalyptic number.

1620331 is a deficient number, since it is larger than the sum of its proper divisors (1).

1620331 is an equidigital number, since it uses as much as digits as its factorization.

1620331 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 108, while the sum is 16.

The square root of 1620331 is about 1272.9222285749. The cubic root of 1620331 is about 117.4540275866.

Adding to 1620331 its reverse (1330261), we get a palindrome (2950592).

The spelling of 1620331 in words is "one million, six hundred twenty thousand, three hundred thirty-one".