21708701801 has 4 divisors (see below), whose sum is σ = 21714808452. Its totient is φ = 21702595152.

The previous prime is 21708701797. The next prime is 21708701851. The reversal of 21708701801 is 10810780712.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1869697600 + 19839004201 = 43240^2 + 140851^2 .

It is a cyclic number.

It is not a de Polignac number, because 21708701801 - 2² = 21708701797 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21708701851) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3047990 + ... + 3055103.

It is an arithmetic number, because the mean of its divisors is an integer number (5428702113).

Almost surely, 2^21708701801 is an apocalyptic number.

It is an amenable number.

21708701801 is a deficient number, since it is larger than the sum of its proper divisors (6106651).

21708701801 is an equidigital number, since it uses as much as digits as its factorization.

21708701801 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6106650.

The product of its (nonzero) digits is 6272, while the sum is 35.

The spelling of 21708701801 in words is "twenty-one billion, seven hundred eight million, seven hundred one thousand, eight hundred one".