21755746 has 16 divisors (see below), whose sum is σ = 34372800. Its totient is φ = 10307088.

The previous prime is 21755717. The next prime is 21755761. The reversal of 21755746 is 64755712.

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, 2845 + ... + 7183.

It is an arithmetic number, because the mean of its divisors is an integer number (2148300).

Almost surely, 2^21755746 is an apocalyptic number.

21755746 is a deficient number, since it is larger than the sum of its proper divisors (12617054).

21755746 is a wasteful number, since it uses less digits than its factorization.

21755746 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4473.

The product of its digits is 58800, while the sum is 37.

The square root of 21755746 is about 4664.3055217256. The cubic root of 21755746 is about 279.1630877193.

It can be divided in two parts, 2175 and 5746, that added together give a square (7921 = 89²).

The spelling of 21755746 in words is "twenty-one million, seven hundred fifty-five thousand, seven hundred forty-six".