21605701433 has 4 divisors (see below), whose sum is σ = 21606852480. Its totient is φ = 21604550388.

The previous prime is 21605701427. The next prime is 21605701451. The reversal of 21605701433 is 33410750612.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21605701433 - 2⁴ = 21605701417 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21605701433.

It is not an unprimeable number, because it can be changed into a prime (21605701463) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 546893 + ... + 585066.

It is an arithmetic number, because the mean of its divisors is an integer number (5401713120).

Almost surely, 2^21605701433 is an apocalyptic number.

It is an amenable number.

21605701433 is a deficient number, since it is larger than the sum of its proper divisors (1151047).

21605701433 is a wasteful number, since it uses less digits than its factorization.

21605701433 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1151046.

The product of its (nonzero) digits is 15120, while the sum is 32.

The spelling of 21605701433 in words is "twenty-one billion, six hundred five million, seven hundred one thousand, four hundred thirty-three".