21421461 has 4 divisors (see below), whose sum is σ = 28561952. Its totient is φ = 14280972.

The previous prime is 21421453. The next prime is 21421489. The reversal of 21421461 is 16412412.

It is a happy number.

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.

It is not a de Polignac number, because 21421461 - 2³ = 21421453 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 (21421451) 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, 3570241 + ... + 3570246.

It is an arithmetic number, because the mean of its divisors is an integer number (7140488).

Almost surely, 2^21421461 is an apocalyptic number.

It is an amenable number.

21421461 is a deficient number, since it is larger than the sum of its proper divisors (7140491).

21421461 is an equidigital number, since it uses as much as digits as its factorization.

21421461 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7140490.

The product of its digits is 384, while the sum is 21.

The square root of 21421461 is about 4628.3324210778. The cubic root of 21421461 is about 277.7258870122.

Adding to 21421461 its reverse (16412412), we get a palindrome (37833873).

The spelling of 21421461 in words is "twenty-one million, four hundred twenty-one thousand, four hundred sixty-one".