1621006 has 4 divisors (see below), whose sum is σ = 2431512. Its totient is φ = 810502.

The previous prime is 1620989. The next prime is 1621019. The reversal of 1621006 is 6001261.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 405250 + ... + 405253.

It is an arithmetic number, because the mean of its divisors is an integer number (607878).

2^1621006 is an apocalyptic number.

1621006 is a deficient number, since it is larger than the sum of its proper divisors (810506).

1621006 is an equidigital number, since it uses as much as digits as its factorization.

1621006 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 810505.

The product of its (nonzero) digits is 72, while the sum is 16.

The square root of 1621006 is about 1273.1873389254. The cubic root of 1621006 is about 117.4703350493.

Adding to 1621006 its reverse (6001261), we get a palindrome (7622267).

The spelling of 1621006 in words is "one million, six hundred twenty-one thousand, six".