2661421 has 4 divisors (see below), whose sum is σ = 3041632. Its totient is φ = 2281212.

The previous prime is 2661419. The next prime is 2661427. The reversal of 2661421 is 1241662.

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: 1241662 = 2 ⋅620831.

It is a cyclic number.

It is not a de Polignac number, because 2661421 - 2¹ = 2661419 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a nialpdrome in base 12.

It is a junction number, because it is equal to n+sod(n) for n = 2661392 and 2661401.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2661427) 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, 190095 + ... + 190108.

It is an arithmetic number, because the mean of its divisors is an integer number (760408).

2^2661421 is an apocalyptic number.

It is an amenable number.

2661421 is a deficient number, since it is larger than the sum of its proper divisors (380211).

2661421 is an equidigital number, since it uses as much as digits as its factorization.

2661421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 380210.

The product of its digits is 576, while the sum is 22.

The square root of 2661421 is about 1631.3862203660. The cubic root of 2661421 is about 138.5812666292.

The spelling of 2661421 in words is "two million, six hundred sixty-one thousand, four hundred twenty-one".