21122371 has 4 divisors (see below), whose sum is σ = 21143200. Its totient is φ = 21101544.

The previous prime is 21122363. The next prime is 21122383. The reversal of 21122371 is 17322112.

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 21122371 - 2³ = 21122363 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21122351) 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, 8811 + ... + 10948.

It is an arithmetic number, because the mean of its divisors is an integer number (5285800).

Almost surely, 2^21122371 is an apocalyptic number.

21122371 is a deficient number, since it is larger than the sum of its proper divisors (20829).

21122371 is a wasteful number, since it uses less digits than its factorization.

21122371 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20828.

The product of its digits is 168, while the sum is 19.

The square root of 21122371 is about 4595.9080713174. The cubic root of 21122371 is about 276.4272726350.

Adding to 21122371 its reverse (17322112), we get a palindrome (38444483).

The spelling of 21122371 in words is "twenty-one million, one hundred twenty-two thousand, three hundred seventy-one".