21441431 has 8 divisors (see below), whose sum is σ = 23441664. Its totient is φ = 19449720.

The previous prime is 21441421. The next prime is 21441449. The reversal of 21441431 is 13414412.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21441431 - 2¹⁸ = 21179287 is a prime.

It is a super-2 number, since 2×21441431² = 919469926655522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21441421) 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, 3890 + ... + 7616.

It is an arithmetic number, because the mean of its divisors is an integer number (2930208).

Almost surely, 2^21441431 is an apocalyptic number.

21441431 is a deficient number, since it is larger than the sum of its proper divisors (2000233).

21441431 is a wasteful number, since it uses less digits than its factorization.

21441431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4261.

The product of its digits is 384, while the sum is 20.

The square root of 21441431 is about 4630.4892830024. The cubic root of 21441431 is about 277.8121628486.

Adding to 21441431 its reverse (13414412), we get a palindrome (34855843).

The spelling of 21441431 in words is "twenty-one million, four hundred forty-one thousand, four hundred thirty-one".