21605634750701 has 8 divisors (see below), whose sum is σ = 21616117095960. Its totient is φ = 21595154953792.

The previous prime is 21605634750647. The next prime is 21605634750703. The reversal of 21605634750701 is 10705743650612.

It can be written as a sum of positive squares in 4 ways, for example, as 5297242877476 + 16308391873225 = 2301574^2 + 4038365^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21605634750701 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21605634750703) 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, 16434335 + ... + 17700243.

It is an arithmetic number, because the mean of its divisors is an integer number (2702014636995).

Almost surely, 2^{21605634750701} is an apocalyptic number.

It is an amenable number.

21605634750701 is a deficient number, since it is larger than the sum of its proper divisors (10482345259).

21605634750701 is a wasteful number, since it uses less digits than its factorization.

21605634750701 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1274175.

The product of its (nonzero) digits is 1058400, while the sum is 47.

The spelling of 21605634750701 in words is "twenty-one trillion, six hundred five billion, six hundred thirty-four million, seven hundred fifty thousand, seven hundred one".