1421661 has 4 divisors (see below), whose sum is σ = 1895552. Its totient is φ = 947772.

The previous prime is 1421647. The next prime is 1421663. The reversal of 1421661 is 1661241.

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, and also an emirpimes, since its reverse is a distinct semiprime: 1661241 = 3 ⋅553747.

It is not a de Polignac number, because 1421661 - 2¹⁸ = 1159517 is a prime.

It is a super-2 number, since 2×1421661² = 4042239997842, which contains 22 as substring.

It is a D-number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1421663) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 236941 + ... + 236946.

It is an arithmetic number, because the mean of its divisors is an integer number (473888).

2^1421661 is an apocalyptic number.

It is an amenable number.

1421661 is a deficient number, since it is larger than the sum of its proper divisors (473891).

1421661 is an equidigital number, since it uses as much as digits as its factorization.

1421661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 473890.

The product of its digits is 288, while the sum is 21.

The square root of 1421661 is about 1192.3342652126. The cubic root of 1421661 is about 112.4428944747.

The spelling of 1421661 in words is "one million, four hundred twenty-one thousand, six hundred sixty-one".