21433131 has 12 divisors (see below), whose sum is σ = 31019352. Its totient is φ = 14260896.

The previous prime is 21433129. The next prime is 21433133. The reversal of 21433131 is 13133412.

It is an interprime number because it is at equal distance from previous prime (21433129) and next prime (21433133).

It is not a de Polignac number, because 21433131 - 2¹ = 21433129 is a prime.

It is a super-2 number, since 2×21433131² = 918758208926322, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21433133) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3255 + ... + 7311.

It is an arithmetic number, because the mean of its divisors is an integer number (2584946).

Almost surely, 2^21433131 is an apocalyptic number.

21433131 is a deficient number, since it is larger than the sum of its proper divisors (9586221).

21433131 is a wasteful number, since it uses less digits than its factorization.

21433131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4650 (or 4647 counting only the distinct ones).

The product of its digits is 216, while the sum is 18.

The square root of 21433131 is about 4629.5929626696. The cubic root of 21433131 is about 277.7763110974.

Adding to 21433131 its reverse (13133412), we get a palindrome (34566543).

The spelling of 21433131 in words is "twenty-one million, four hundred thirty-three thousand, one hundred thirty-one".