21769308 has 36 divisors (see below), whose sum is σ = 60031608. Its totient is φ = 6596640.

The previous prime is 21769301. The next prime is 21769313. The reversal of 21769308 is 80396712.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21769301) 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 11 ways as a sum of consecutive naturals, for example, 27091 + ... + 27882.

Almost surely, 2^21769308 is an apocalyptic number.

It is an amenable number.

21769308 is an abundant number, since it is smaller than the sum of its proper divisors (38262300).

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

21769308 is a wasteful number, since it uses less digits than its factorization.

21769308 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54994 (or 54989 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 36.

The square root of 21769308 is about 4665.7591022255. The cubic root of 21769308 is about 279.2210834838.

The spelling of 21769308 in words is "twenty-one million, seven hundred sixty-nine thousand, three hundred eight".