21775080 has 32 divisors (see below), whose sum is σ = 65325600. Its totient is φ = 5806656.

The previous prime is 21775069. The next prime is 21775093. The reversal of 21775080 is 8057712.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 90610 + ... + 90849.

It is an arithmetic number, because the mean of its divisors is an integer number (2041425).

Almost surely, 2^21775080 is an apocalyptic number.

21775080 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21775080 is an abundant number, since it is smaller than the sum of its proper divisors (43550520).

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

21775080 is a wasteful number, since it uses less digits than its factorization.

21775080 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 181473 (or 181469 counting only the distinct ones).

The product of its (nonzero) digits is 3920, while the sum is 30.

The square root of 21775080 is about 4666.3776100954. The cubic root of 21775080 is about 279.2457592287.

The spelling of 21775080 in words is "twenty-one million, seven hundred seventy-five thousand, eighty".