21771408 has 20 divisors (see below), whose sum is σ = 56242928. Its totient is φ = 7257120.

The previous prime is 21771391. The next prime is 21771427. The reversal of 21771408 is 80417712.

It is a hoax number, since the sum of its digits (30) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 226738 + ... + 226833.

Almost surely, 2^21771408 is an apocalyptic number.

It is an amenable number.

21771408 is an abundant number, since it is smaller than the sum of its proper divisors (34471520).

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

21771408 is a wasteful number, since it uses less digits than its factorization.

21771408 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 453582 (or 453576 counting only the distinct ones).

The product of its (nonzero) digits is 3136, while the sum is 30.

The square root of 21771408 is about 4665.9841405646. The cubic root of 21771408 is about 279.2300616504.

The spelling of 21771408 in words is "twenty-one million, seven hundred seventy-one thousand, four hundred eight".