21631127 has 4 divisors (see below), whose sum is σ = 24721296. Its totient is φ = 18540960.

The previous prime is 21631121. The next prime is 21631171. The reversal of 21631127 is 72113612.

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

It is a cyclic number.

It is not a de Polignac number, because 21631127 - 2⁸ = 21630871 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 (21631121) 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, 1545074 + ... + 1545087.

It is an arithmetic number, because the mean of its divisors is an integer number (6180324).

Almost surely, 2^21631127 is an apocalyptic number.

21631127 is a deficient number, since it is larger than the sum of its proper divisors (3090169).

21631127 is an equidigital number, since it uses as much as digits as its factorization.

21631127 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3090168.

The product of its digits is 504, while the sum is 23.

The square root of 21631127 is about 4650.9275418996. The cubic root of 21631127 is about 278.6290424150.

Adding to 21631127 its reverse (72113612), we get a palindrome (93744739).

The spelling of 21631127 in words is "twenty-one million, six hundred thirty-one thousand, one hundred twenty-seven".