21773436 has 12 divisors (see below), whose sum is σ = 50804712. Its totient is φ = 7257808.

The previous prime is 21773431. The next prime is 21773441. The reversal of 21773436 is 63437712.

It is an interprime number because it is at equal distance from previous prime (21773431) and next prime (21773441).

It is a tau number, because it is divible by the number of its divisors (12).

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 21773397 and 21773406.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21773431) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 907215 + ... + 907238.

It is an arithmetic number, because the mean of its divisors is an integer number (4233726).

Almost surely, 2^21773436 is an apocalyptic number.

It is an amenable number.

21773436 is an abundant number, since it is smaller than the sum of its proper divisors (29031276).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21773436 is a wasteful number, since it uses less digits than its factorization.

21773436 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1814460 (or 1814458 counting only the distinct ones).

The product of its digits is 21168, while the sum is 33.

The square root of 21773436 is about 4666.2014530022. The cubic root of 21773436 is about 279.2387314462.

The spelling of 21773436 in words is "twenty-one million, seven hundred seventy-three thousand, four hundred thirty-six".