1620399 has 8 divisors (see below), whose sum is σ = 2356992. Its totient is φ = 982040.

The previous prime is 1620391. The next prime is 1620403. The reversal of 1620399 is 9930261.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1620399 - 2³ = 1620391 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1620391) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 24519 + ... + 24584.

It is an arithmetic number, because the mean of its divisors is an integer number (294624).

2^1620399 is an apocalyptic number.

1620399 is a deficient number, since it is larger than the sum of its proper divisors (736593).

1620399 is a wasteful number, since it uses less digits than its factorization.

1620399 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49117.

The product of its (nonzero) digits is 2916, while the sum is 30.

The square root of 1620399 is about 1272.9489384889. The cubic root of 1620399 is about 117.4556706176.

The spelling of 1620399 in words is "one million, six hundred twenty thousand, three hundred ninety-nine".