1620421 has 4 divisors (see below), whose sum is σ = 1767744. Its totient is φ = 1473100.

The previous prime is 1620413. The next prime is 1620431. The reversal of 1620421 is 1240261.

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 a cyclic number.

It is not a de Polignac number, because 1620421 - 2³ = 1620413 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1620395 and 1620404.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1620431) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 73645 + ... + 73666.

It is an arithmetic number, because the mean of its divisors is an integer number (441936).

2^1620421 is an apocalyptic number.

1620421 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1620421 is a deficient number, since it is larger than the sum of its proper divisors (147323).

1620421 is a wasteful number, since it uses less digits than its factorization.

1620421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 147322.

The product of its (nonzero) digits is 96, while the sum is 16.

The square root of 1620421 is about 1272.9575798117. The cubic root of 1620421 is about 117.4562021766.

Adding to 1620421 its reverse (1240261), we get a palindrome (2860682).

The spelling of 1620421 in words is "one million, six hundred twenty thousand, four hundred twenty-one".