21484731 has 4 divisors (see below), whose sum is σ = 28646312. Its totient is φ = 14323152.

The previous prime is 21484721. The next prime is 21484747. The reversal of 21484731 is 13748412.

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

It is not a de Polignac number, because 21484731 - 2⁵ = 21484699 is a prime.

It is a super-2 number, since 2×21484731² = 923187332284722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21484721) 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, 3580786 + ... + 3580791.

It is an arithmetic number, because the mean of its divisors is an integer number (7161578).

Almost surely, 2^21484731 is an apocalyptic number.

21484731 is a deficient number, since it is larger than the sum of its proper divisors (7161581).

21484731 is an equidigital number, since it uses as much as digits as its factorization.

21484731 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7161580.

The product of its digits is 5376, while the sum is 30.

The square root of 21484731 is about 4635.1624566999. The cubic root of 21484731 is about 277.9990468025. Note that the first 3 decimals are identical.

The spelling of 21484731 in words is "twenty-one million, four hundred eighty-four thousand, seven hundred thirty-one".