1201621 has 4 divisors (see below), whose sum is σ = 1205100. Its totient is φ = 1198144.

The previous prime is 1201601. The next prime is 1201633. The reversal of 1201621 is 1261021.

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

It can be written as a sum of positive squares in 2 ways, for example, as 731025 + 470596 = 855^2 + 686^2 .

It is a cyclic number.

It is not a de Polignac number, because 1201621 - 2⁷ = 1201493 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1201601) 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, 1156 + ... + 1933.

It is an arithmetic number, because the mean of its divisors is an integer number (301275).

2^1201621 is an apocalyptic number.

It is an amenable number.

1201621 is a deficient number, since it is larger than the sum of its proper divisors (3479).

1201621 is an equidigital number, since it uses as much as digits as its factorization.

1201621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3478.

The product of its (nonzero) digits is 24, while the sum is 13.

The square root of 1201621 is about 1096.1847472028. The cubic root of 1201621 is about 106.3136845429.

Adding to 1201621 its reverse (1261021), we get a palindrome (2462642).

The spelling of 1201621 in words is "one million, two hundred one thousand, six hundred twenty-one".