1321620 has 24 divisors (see below), whose sum is σ = 3700704. Its totient is φ = 352416.

The previous prime is 1321601. The next prime is 1321627. The reversal of 1321620 is 261231.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 1321620.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1321627) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10954 + ... + 11073.

It is an arithmetic number, because the mean of its divisors is an integer number (154196).

2^1321620 is an apocalyptic number.

1321620 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1321620 is an abundant number, since it is smaller than the sum of its proper divisors (2379084).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1321620 is a wasteful number, since it uses less digits than its factorization.

1321620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22039 (or 22037 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 15.

The square root of 1321620 is about 1149.6173276356. The cubic root of 1321620 is about 109.7409883929.

Adding to 1321620 its reverse (261231), we get a palindrome (1582851).

The spelling of 1321620 in words is "one million, three hundred twenty-one thousand, six hundred twenty".