21771413 has 4 divisors (see below), whose sum is σ = 22140480. Its totient is φ = 21402348.

The previous prime is 21771391. The next prime is 21771427. The reversal of 21771413 is 31417712.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21771413 - 2⁸ = 21771157 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 (21771443) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 184445 + ... + 184562.

It is an arithmetic number, because the mean of its divisors is an integer number (5535120).

Almost surely, 2^21771413 is an apocalyptic number.

It is an amenable number.

21771413 is a deficient number, since it is larger than the sum of its proper divisors (369067).

21771413 is an equidigital number, since it uses as much as digits as its factorization.

21771413 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 369066.

The product of its digits is 1176, while the sum is 26.

The square root of 21771413 is about 4665.9846763572. The cubic root of 21771413 is about 279.2300830263.

The spelling of 21771413 in words is "twenty-one million, seven hundred seventy-one thousand, four hundred thirteen".