21741775 has 24 divisors (see below), whose sum is σ = 29645424. Its totient is φ = 15686400.

The previous prime is 21741749. The next prime is 21741781. The reversal of 21741775 is 57714712.

It is not a de Polignac number, because 21741775 - 2⁵ = 21741743 is a prime.

It is a hoax number, since the sum of its digits (34) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21741775.

It is a congruent number.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 47347 + ... + 47803.

It is an arithmetic number, because the mean of its divisors is an integer number (1235226).

Almost surely, 2^21741775 is an apocalyptic number.

21741775 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21741775 is a deficient number, since it is larger than the sum of its proper divisors (7903649).

21741775 is a wasteful number, since it uses less digits than its factorization.

With its successor (21741776) it forms a Ruth-Aaron pair, since the sum of their distinct prime factors is the same (646).

With its successor (21741776) it forms an eRAP, since the sums of their prime factors are consecutive (651 and 652).

21741775 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 651 (or 646 counting only the distinct ones).

The product of its digits is 13720, while the sum is 34.

The square root of 21741775 is about 4662.8076306020. The cubic root of 21741775 is about 279.1033177216.

The spelling of 21741775 in words is "twenty-one million, seven hundred forty-one thousand, seven hundred seventy-five".