21765422 has 16 divisors (see below), whose sum is σ = 37763712. Its totient is φ = 9215160.

The previous prime is 21765421. The next prime is 21765427. The reversal of 21765422 is 22456712.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21765421) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8204 + ... + 10527.

It is an arithmetic number, because the mean of its divisors is an integer number (2360232).

Almost surely, 2^21765422 is an apocalyptic number.

21765422 is a deficient number, since it is larger than the sum of its proper divisors (15998290).

21765422 is a wasteful number, since it uses less digits than its factorization.

21765422 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18823.

The product of its digits is 6720, while the sum is 29.

The square root of 21765422 is about 4665.3426455085. The cubic root of 21765422 is about 279.2044680774.

The spelling of 21765422 in words is "twenty-one million, seven hundred sixty-five thousand, four hundred twenty-two".