21131043 has 8 divisors (see below), whose sum is σ = 29399808. Its totient is φ = 13474824.

The previous prime is 21131041. The next prime is 21131069. The reversal of 21131043 is 34013112.

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

It is not a de Polignac number, because 21131043 - 2¹ = 21131041 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21131041) 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, 153055 + ... + 153192.

It is an arithmetic number, because the mean of its divisors is an integer number (3674976).

Almost surely, 2^21131043 is an apocalyptic number.

21131043 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

21131043 is a deficient number, since it is larger than the sum of its proper divisors (8268765).

21131043 is a wasteful number, since it uses less digits than its factorization.

21131043 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 306273.

The product of its (nonzero) digits is 72, while the sum is 15.

The square root of 21131043 is about 4596.8514224412. The cubic root of 21131043 is about 276.4650974500.

Adding to 21131043 its reverse (34013112), we get a palindrome (55144155).

The spelling of 21131043 in words is "twenty-one million, one hundred thirty-one thousand, forty-three".