21609795 has 16 divisors (see below), whose sum is σ = 34895520. Its totient is φ = 11418624.

The previous prime is 21609787. The next prime is 21609817. The reversal of 21609795 is 59790612.

It is not a de Polignac number, because 21609795 - 2³ = 21609787 is a prime.

It is a super-4 number, since 4×21609795⁴ (a number of 30 digits) contains 4444 as substring.

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 15 ways as a sum of consecutive naturals, for example, 4974 + ... + 8243.

It is an arithmetic number, because the mean of its divisors is an integer number (2180970).

Almost surely, 2^21609795 is an apocalyptic number.

21609795 is a deficient number, since it is larger than the sum of its proper divisors (13285725).

21609795 is a wasteful number, since it uses less digits than its factorization.

21609795 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13334.

The product of its (nonzero) digits is 34020, while the sum is 39.

The square root of 21609795 is about 4648.6336702304. The cubic root of 21609795 is about 278.5374202872.

The spelling of 21609795 in words is "twenty-one million, six hundred nine thousand, seven hundred ninety-five".