1621213 has 8 divisors (see below), whose sum is σ = 1861920. Its totient is φ = 1396080.

The previous prime is 1621177. The next prime is 1621219. The reversal of 1621213 is 3121261.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1621213 is a prime.

It is a Duffinian number.

It is a plaindrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1621219) 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, 3670 + ... + 4087.

It is an arithmetic number, because the mean of its divisors is an integer number (232740).

2^1621213 is an apocalyptic number.

It is an amenable number.

1621213 is a deficient number, since it is larger than the sum of its proper divisors (240707).

1621213 is a wasteful number, since it uses less digits than its factorization.

1621213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7787.

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

The square root of 1621213 is about 1273.2686283734. The cubic root of 1621213 is about 117.4753350975.

Adding to 1621213 its reverse (3121261), we get a palindrome (4742474).

The spelling of 1621213 in words is "one million, six hundred twenty-one thousand, two hundred thirteen".