21795405 has 32 divisors (see below), whose sum is σ = 36180864. Its totient is φ = 11195136.

The previous prime is 21795401. The next prime is 21795427. The reversal of 21795405 is 50459712.

It is not a de Polignac number, because 21795405 - 2² = 21795401 is a prime.

It is a super-2 number, since 2×21795405² = 950079358228050, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21795401) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 95902 + ... + 96128.

It is an arithmetic number, because the mean of its divisors is an integer number (1130652).

Almost surely, 2^21795405 is an apocalyptic number.

It is an amenable number.

21795405 is a deficient number, since it is larger than the sum of its proper divisors (14385459).

21795405 is a wasteful number, since it uses less digits than its factorization.

21795405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 445.

The product of its (nonzero) digits is 12600, while the sum is 33.

The square root of 21795405 is about 4668.5549156029. The cubic root of 21795405 is about 279.3326154740.

The spelling of 21795405 in words is "twenty-one million, seven hundred ninety-five thousand, four hundred five".