21775316 has 12 divisors (see below), whose sum is σ = 38629332. Its totient is φ = 10738368.

The previous prime is 21775309. The next prime is 21775321. The reversal of 21775316 is 61357712.

It can be written as a sum of positive squares in 2 ways, for example, as 13912900 + 7862416 = 3730^2 + 2804^2 .

It is a congruent number.

It is an unprimeable number.

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, 36995 + ... + 37578.

It is an arithmetic number, because the mean of its divisors is an integer number (3219111).

Almost surely, 2^21775316 is an apocalyptic number.

It is an amenable number.

21775316 is a deficient number, since it is larger than the sum of its proper divisors (16854016).

21775316 is a wasteful number, since it uses less digits than its factorization.

21775316 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74650 (or 74648 counting only the distinct ones).

The product of its digits is 8820, while the sum is 32.

The square root of 21775316 is about 4666.4028973075. The cubic root of 21775316 is about 279.2467680541.

The spelling of 21775316 in words is "twenty-one million, seven hundred seventy-five thousand, three hundred sixteen".